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The Set-Up of a Foundation Colorant File for the Purpose of Color-Matching Foundations, With a View to Improving the Current Foundation Color-Matching
Process in the Future
Hannah Hedenström
Master of Science Thesis
Stockholm, Sweden 2011
Supervisor: Michelle Allen, Senior Color Analyst
Dr Linda Fogelström Examiner:
Prof. Eva Malmström
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Abstract The process of color-‐matching any color product is a process that can be quite complicated and requires great skill from a color analyst. As the name suggests color-‐matching is the process in which the color of a standard is obtained from a sample through careful inspection and precision in order for the colors to match up. It is a process that can vary in length dependent of the amount of pigments used. Foundations are a type of liquid emulsion cosmetic and consist of five main pigments; white (titanium dioxide), red, brown, yellow and black iron oxides. These five pigments can when mixed together result in hundreds of shades. One of the greatest challenges for cosmetics companies is to successfully manufacture these shades often from a benchmark, a desired shade, as well as maintaining this same shade when the batch is scaled up from lab production to factory. Oriflame is a direct-‐selling cosmetics company in which the Marketing department and Color Cosmetic department work closely in order to produce new products and shades for each catalogue. Liquid foundation shades are decided by the Marketing department and given to the Color Cosmetic department to color-‐match. Currently the process of color-‐matching is carried out through the visual assessment by the color analyst. In order to improve the efficiency and lead -‐ time of the current method, Oriflame has drawn inspiration from other sectors dealing with color and taken the decision to color-‐match with the use of a spectrophotometer coupled with color-‐appropriate software. The method was divided into four separate processes; confirming a sample method presentation to the spectrophotometer, colorant file set-‐up & process, color-‐matching process with the color-‐appropriate software and color match comparison. The results showed that with an adequate sized colorant file a method for color-‐matching with a spectrophotometer was established. The lead-‐time could be decreased by, as much as 66.6 % and providing strong evidence that this is a valuable tool for color analysts working at Oriflame.
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1 Table of Contents
1 INTRODUCTION .......................................................................................................................................4 1.1 LIQUID FOUNDATIONS ........................................................................................................................................... 4 1.2 FOUNDATIONS COMPONENTS............................................................................................................................... 5 1.2.1 The oil phase .....................................................................................................................................................5 1.2.2 The powder phase...........................................................................................................................................5 1.2.3 The Silicone phase ..........................................................................................................................................8 1.2.4 The Water Phase .............................................................................................................................................9 1.2.5 The Foundation Manufacture Process...................................................................................................9
1.3 FILM DEPOSITION OF THE FOUNDATION......................................................................................................... 10 1.4 THE CONCEPT OF COLOR.................................................................................................................................... 11 1.4.1 The first factor of color perception – The Light Source .............................................................. 11 1.4.2 The second factor of color perception – The Object ..................................................................... 12 1.4.3 The third factor of color perception – The human observer..................................................... 14 1.4.4 Color Communication ................................................................................................................................ 15
1.5 COLOR COMMUNICATION WITHIN THE INDUSTRIAL SECTOR ...................................................................... 16 1.6 COLOR-‐MATCHING FOUNDATIONS .................................................................................................................... 18 1.7 INVESTIGATING THE POSSIBILITY OF DIGITALIZING THE PROCESS OF COLOR – MATCHING WITH COLOR APPROPRIATE SOFTWARE AT ORIFLAME R & D ........................................................................................................ 19
2 AIM OF THE THESIS ............................................................................................................................. 20 3 DEFINITIONS AND TERMS................................................................................................................. 20 4 EXPERIMENTAL PART ........................................................................................................................ 21 4.1 CONFIRMING A SAMPLE PRESENTATION METHOD TO THE SPECTROPHOTOMETER ................................ 21 4.1.1 Instrumentation ........................................................................................................................................... 21 4.1.2 Method.............................................................................................................................................................. 21 4.1.3 Results............................................................................................................................................................... 22
4.2 COLORANT FILE SET-‐UP AND PROCESS ........................................................................................................... 22 4.2.1 Blender Manufacture ................................................................................................................................. 22 4.2.2 Mix Manufacture.......................................................................................................................................... 23 4.2.3 The Set – Up of a Colorant File and Entering the Mixes Into the Colorant File ................ 23 4.2.4 Results............................................................................................................................................................... 26
4.3 COLOR–MATCHING PROCESS WITH THE COLOR IMATCH SOFTWARE ...................................................... 32 4.3.1 Instrumentation ........................................................................................................................................... 32 4.3.2 Method.............................................................................................................................................................. 32 4.3.3 Challenges When Color-Matching with the Color iMatch Software ...................................... 35 4.3.4 Resolving the Challenges .......................................................................................................................... 40 4.3.5 Results............................................................................................................................................................... 47
4.4 COLOR–MATCHING COMPARISON .................................................................................................................... 47 4.4.1 Method.............................................................................................................................................................. 47 4.4.2 Results............................................................................................................................................................... 47
5 RESULTS FROM THE FOUR PROCESSES ........................................................................................ 48 6 CONCLUSIONS FROM THE FOUR PROCESSES .............................................................................. 53 7 FUTURE INVESTIGATIONS ................................................................................................................ 53 8 ACKNOWLEDGEMENTS ...................................................................................................................... 54 9 BIBLIOGRAPHY..................................................................................................................................... 55
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1 Introduction Since the launch of the first foundation in 1937 known as the pan-‐cake make up, foundations have evolved from cake like textures to high tech science emulsions designed to mimic the skin’s physiology. Liquid foundations are emulsions composed of pigments applied to the face with the purpose of evening out skin tones and masking minor imperfections. With the use of five main pigments; titanium dioxide, red, brown, yellow and black iron oxide hundreds of shades can be produced with minor differences developed to suit as many skin tones as possible. One of the greatest challenges for cosmetics companies is to successfully manufacture these shades often from a benchmark, a desired shade, as well as maintaining this same shade when the batch is scaled up from lab production to factory. In order to facilitate the process of color-‐matching, matching the color of one shade to a benchmark so that the two are as close as possible, cosmetic companies have turned to the set-‐up of a digital colorant file in order to increase the efficiency of the current method. This set-‐up involves preparing known mixtures of different pigment amounts entering them with a spectrophotometer and storing them in a color-‐appropriate software database. Oriflame, a direct-‐selling cosmetic company, was founded in 1976 by the af Jochnick brothers, the corporate headquarters are located in Stockholm, Sweden while the Research & Development facility is located in Dublin, Ireland. The Marketing department and Color Cosmetic team work closely in order to produce new shades and products for each catalogue. In the case of liquid foundations, the desired shades, benchmarks, are determined by the Marketing team and given to the color analysts to color-‐match. The current method of color-‐matching is carried out through the traditional method in which the color analyst must rely on their eyesight. This thesis will focus on the set-‐up of a foundation colorant file for the purpose of color-‐matching foundations in order to insure an efficient method as well as decreasing the lead-‐time in color-‐matching foundations at Oriflame Research & Development.
1.1 Liquid Foundations Liquid foundations are a color cosmetic with the function to impact a smooth finish when applied to the skin, masking minor imperfections and evening out skin tones. [24] It must be blendable having an adequate play time, should not be greasy or occlusive to the skin, and must feel comfortable to the consumer as well as not sinking into facial lines. [8] Foundations are emulsion-‐based formulations, containing pigments, dispersants, emulsifiers and preservatives and are applied to the skin either by hand or with the aid of a sponge or brush. There are three major types of emulsified foundations in which the pigments can be suspended in; oil-‐in-‐water, water-‐in-‐oil, or water-‐in-‐silicone emulsions. The latter, water-‐in-‐silicone emulsion based systems have become increasingly popular as they are water resistant and create an elegant non-‐greasy feel. They have also become increasingly popular as silicones have a variety of film-‐forming characteristics. [20]
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The previous two emulsion systems; oil-‐in-‐water and water-‐in-‐oil systems can be quite challenging to manufacture and have therefore been replaced by water-‐in-‐silicone systems. Oil-‐in-‐ water systems can be classified as anionic, cationic or amphoteric depending on the type of emulsifier used. Out of the three systems the anionic system is the most favored as they are easier to formulate with as most pigments and fillers carry a negative charge near to pH 7. [24] Water-‐in-‐oil emulsions are avoided as the produced foundation has a greasy skin feel and result in higher production costs.
1.2 Foundations Components Foundations are for the most part, regardless of the emulsion used, classified into three main components the oil phase, powder phase, and water phase. The oil phase is composed of both waxes and oils in order to ensure good pigment dispersion and viscosity control. The powder phase is composed of both pigments and extenders. Lastly, the water phase contains water and certain wetting agents. The exact separate components made up within each phase are specific to the individual emulsion. As this thesis will focus on the color-‐matching of water-‐in-‐silicone foundations, the components specific to this emulsion are presented.
1.2.1 The oil phase The oil phase of a silicone-‐in-‐water foundation contains organofunctional silicones such as cetyl dimethicone used as an emollient, silicone emulsifiers such as dimethicone copolyols and thickening agents such as hydrogenated castor oil. [31] Apart from this, preservatives, most often a propylparaben, are added as well as additional sunscreen filters in the form of BHT.
1.2.2 The powder phase The powder phase consists of the pigments and fillers. The pigments are divided into two categories; the white and the colored. Both types are inorganic occurring naturally or synthesized through industrial processes. As these pigments are inorganic they must be chemically treated with silicone in order to insure that the pigments do not aggregate.
1.2.2.1 The white pigments Titanium dioxide is the most commonly used white pigment, out of the three main available pigments. Not only does it provide excellent coverage, thanks to its high refractive index, but it also acts as a sunscreen. The second most frequently used oxide, zinc oxide, has in comparison to titanium dioxide a lower refractive index thus giving a lower coverage. It is also a more yellow-‐white color and is therefore used when producing shades of darker colors. However, there is a restraint when dealing with zinc oxide, notably the formations of Zn2+ in the water phase, which occurs when the pH level is below six, causing a separation of phases. Last but not least, kaolin, a hydrous
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aluminum silicate, known as a filler pigment is incorporated giving a smooth feel to dispersed systems as well as providing coverage. [24]
1.2.2.2 The colored pigments Red, yellow and black iron oxides are the principle colored oxides used in foundation make up. [24] These three iron oxides are inorganic and are mixed in appropriate quantities to achieve the desired shade. These inorganic pigments are found naturally or can be synthesized from byproducts from other industries. There are 16 iron oxides, comprised of iron hydroxides, iron oxides, and oxide – hydroxides.i In the majority of the iron oxides, the iron is in the FeIII state. Of the 16 iron oxides 4 oxides are used as pigments, hematite (α-‐Fe2-‐O3), goethite (α-‐FeOOH), lepidocrocite (γ-‐FeOOH) and magnetite (Fe3O4). The four are found naturally in soils and have different characteristic colors, but can also be synthesized from different raw materials. The four oxides are described separately below as well as the industrial processes in which they are obtained. Hematite (α-‐Fe2-‐O3) Hematite originates from the word haimo, referring to blood and is a dull red color. [14] Hematite is the most common found iron species. It has a long history of being the main colorant in order to produce pigment shade such as red, brown, and purple iron–oxide based pigments. Hematite can be synthetically produced through various methods; one of the most common methods is through the dehydration of goethite at high temperatures (850 – 900 ° C). Other methods include the process known as the direct-‐red process whereby solutions of iron (II) with atmospheric oxidation at 80 °C is added to α-‐Fe2-‐O3. [6] The product is a soft iron oxide pigment with a pure red color.ii Goethite (α-‐FeOOH) This iron hydroxide produces a yellow powder, however, when found in its mineral form it has a brown/black color. Oxidizing iron (II) sulfate mixed with alum and precipitated with an alkali will produce goethite. It is then later used in order to obtain a yellow/brown iron oxide pigment. Lepidocrocite (γ -‐ FeOOH)
ConfidentialConfidentialConfidentialConfidentialConfidentialConfidentialConfidentialConfidentialConfidentialConfidentiali As mentioned in Iron oxides: Structures, Properties, Reactions, Occurrences & Uses the hydroxides, oxides and hydroxide – oxides are referred to as iron oxides. The author of Industrial Inorganic pigments also follows this notation. ii Soft in this context refers to the hardness of the iron oxide.
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The iron oxide hydroxide, lepidocrocite originates from the Greek word for saffron-colored snowflake, which is a suitable name as it has a yellow color. [14] It is far less abundant than the two previously mention iron oxides, with a slightly more complex structure in which sheets of FeOOH are held together by hydrogen bonds.[14] The three most common processes to synthesize lepidocrocite consist of precipitation of various iron (II) compounds. The obtained γ-‐FeOOH is then used to create a yellow pigment. Magnetite (Fe3O4) Magnetite as the name suggests has magnetic properties with a cubic structure occurring as black octahedral crystals. It is one of the most common found iron oxides with many natural deposits globally. As each description of the iron oxides show, several iron oxides can be obtained synthetically through the use of other iron oxides as raw materials. They can also be synthesized through the use of steel scrap, byproduct from deep drawing, titanium dioxide production or steel pickling. It is also important to state that the reaction conditions for all synthetic processes impact on the final pigment size as well as the brightness of the final pigment color. This is best highlighted through the Laux Process, a modification of the Béchamp reaction, in which nitrobenzene is reduced by metallic iron. Through the addition of iron (II) chloride or aluminum chloride solutions, sulfuric acid and phosphoric acid Laux was able to produce high-‐quality iron oxide pigments.[6] By varying the reaction conditions pigment colors such as yellow, red, brown and black can be obtained. For example if iron(II) chloride is added a black pigment is obtained and if the nitro compounds are reduced in the presence of aluminum chloride a yellow iron pigment is attained. Other factors that have an impact on the pigment color obtained are the size of the steel particles, the reaction rate, and the concentration of the additives.
1.2.2.3 Fillers Fillers are added to a foundation to act as extenders for the pigments and to improve the dispersion and decrease the amount of pigment needed. The most common fillers are two silicate derivatives, talc and mica. Talc is a hydrated magnesium aluminum silicate and is the most common filler used in foundations thanks to its low price. Mica, a platy potassium aluminum silicate is in comparison to talc, translucent and harder. It fulfills the function of giving the foundation a smooth, silky feel without additional opacity. A third filler, sericite also a mica, can also be used which has characteristics in between those of talc and mica. Fillers not only improve the dispersion but can also be added to modify the texture and give superior performance.
1.2.2.4 Silicone treated pigments As the pigments are suspended in the silicone phase with an unknown particle size, the iron oxide pigments must be treated with silicone in order to ensure that no pigment aggregations occur. This can be done through two different means either by blending the silicone, usually a dimethiconeiii, where there is no physical bond between the iii Dimethicone is a synonym for polydimethylsiloxane (PDMS), which is further explained in 1.3 The silicone phase.
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pigment and silicone, or through the absorption of silicone on to the surface of the pigment. The second method of silicone treatment is preferred as there is no liberation of hydrogen and no agglomeration of the pigment; leading to a more stable foundation.
1.2.3 The Silicone phase The silicones used within cosmetic formulations are high molecular weight polydimethylsiloxanes (PDMS). They contain a silicone and oxygen backbone to which methyl pendants can be added, figure 1. It is thanks to this backbone that the PDMS backbone is flexible. Not only does PDMS like all other silicones have a low surface tension but it also possesses the ability to spread evenly, and wet almost all surfaces. [20] Further to this, PDMS has a low Tg, set at a temperature lower than -‐120 ° C, and a high permeability to gas. PDMS can consist of linear or cyclic polymer chains and with the replacement of certain methyl groups the required adhesion to certain substrates, polarity and hydrophobicity can be achieved.[20] As a consequence of its low surface tension, low compatibility with both water and aliphatic carbons, silicone fluids, such as those used in foundations, readily separate from other ingredients in a formulation when it is spread over the surface of skin or hair. [19] The silicone will therefore because of its low surface tension and intermolecular binding forces spread over the surface of the other ingredients in the formulation. [19] In general, the work of cohesion, 2σf, of the liquid phase has a surface tension σ that is smaller than the work of adhesion ζsf, to the surface of the substrate so that the spreading pressure p = ζsf -‐ 2σf becomes positive. [19] This results in the silicone found at the surface/air interface of the applied formulation. In liquid foundations, the silicone phase consists of volatile silicones, which act as a carrier fluid and have good pigment deposition properties.[12] Examples of such silicones are the cyclomethicones; cyclopentasiloxane and cyclohexasiloxane as they evaporate leaving a non-‐greasy feel. In Oriflame’s Age Defying Foundation formulation, the foundation formulation used during this thesis the silicone phase consists of a blend of cyclopentasiloxane and cyclohexasiloxane. According to the manufacture, Dow Corning, these fluids are among the more structurally basic film-‐forming silicones. [20] The discussion of siloxanes and their film-‐forming properties will be more thoroughly presented in the following section.
Figure 1 The polymethylsiloxane (PDMS) structure. [20] Figure 0
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1.2.4 The Water Phase The water phases consists of deionized water, preservatives, as well as an inorganic salt in order to favor the migration of the polymeric emulsifier at the water/silicone interface to maintain stability. [24] Other ingredients found in the water phase are chelating agents and viscosity controlling agents.
1.2.5 The Foundation Manufacture Process The different phases are heated and mixed together in specific quantities and specific shearing velocities. The oil phase and silicone phase are heated separately before the silicone phase is added into the oil phase. The pigments are then added at a high sheering velocity, commonly referred to as milling; this is the most important step in order to ensure complete pigment dispersion. It is also an important step in order to insure an adequate pigment particle size. After the intense milling period, the water phase is added to the silicone. This is added at a lower sheering velocity and the forming emulsion is allowed to cool before the preservatives and fragrances are added.
Figure 1 The cyclopentasiloxane and cyclohexasiloxane structures found in the silicone phase.13]
Figure 1 A schematic drawing of the final emulsion formation step.
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1.3 Film Deposition of the Foundation One of the most important aspects of a cosmetic foundation is the deposition of an even film, appearing as natural as possible, in which the pigments are evenly distributed. Foundations, when applied to the skin, dry through a physical process in which the volatile oil phase and water phase evaporate. As this is of great importance polymers have been incorporated into the formulations in order to achieve better film forming qualities. These polymers can consist of siloxanes or polymers such as polyethylene or polyurethanes. Although the exact details of the film deposition process are unclear, studies suggest that the dispersed phase and continuous phase evaporate simultaneously. [4]
Experimental data show that the dispersed aqueous phase initially evaporates at a higher rate than the continuous volatile phase. This was presented through monitoring the volume fractions of each phase as a function of time. Studies also showed that the continuous phase had an influence on the evaporation of the dispersed aqueous phase.
Figure 2 (a) Depicts the residual mass as a function of time. (b) The volume fraction of the dispersed phase as a function of time. [4]
Silicones as previously mentioned in section 1.3 have good film-‐forming properties. Enhanced film-‐forming properties are directly linked to the molecular weight, functionality and structure of the silicone. One can find silicones in the form of volatile fluids to swollen or partially cross-‐linked elastomers. In between these two categories dimethicone crosspolymers can be obtained through platinum-‐catalyzed crosslinking reactions between linear silicone polymers.[20] These materials are often strongly hydrophilic and are more suited towards medical applications, such as drug delivery systems. Furthermore recent developments have led to silicone-‐organic film formers such as silicone polyamides and silicone acrylate copolymers. These copolymers have shown the ability to form a durable film resistant to abrasion and wash-‐off. [19] They have shown promising results when tested with prototype sunscreen formulations, where the sunscreen has remained on the skin after several washes.[20] Perhaps the use of silicone acrylate copolymers could be incorporated into long-‐lasting foundation formulations.
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Synthetic polymers have been applied to hair fixture formulations such as hair spray and gels for the film-‐forming properties. These polymers are largely dominated by acrylates and certain polyvidones. For foundations mostly polyethylene and polyurethanes are used, as the lower Tg temperatures prohibit the formation of a brittle film.
1.4 The Concept of Color The phenomenon of color results from the physical interaction of light with an object and the subjective experience of an individual observer. [17] As the definition states, there are three factors that need to be taken into consideration when defining color; the light source, the object and the observer. These three components influence our color perception and as a result the same color viewed by one individual may not be the same as for another. This highlights the difficulty faced when working with describing color and the need to establish the parameters influencing our perception of color. These three parameters as well as the method used when communicating color will be presented below.
1.4.1 The first factor of color perception – The Light Source A light source is described as an object that emits radiant energy (light) and classified with the electromagnetic spectrum. [17] The visible spectrum, in which humans can view colors, is found between the wavelengths of 380 – 760 nm. As seen below in figure 5. The visible spectrum is only a small part of the electromagnetic spectrum, but it contains the colors spanning from blue at 360 – 480 nm to red at 680 – 700 nm.
Figure 2 The electromagnetic spectrum with the visible wavelength region indicated.[25]
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1.4.2 The second factor of color perception – The Object The second component when perceiving color is the object; its shape and form will modify and distribute the light waves that interact with them. [17] This distribution is a direct consequence of the object’s geometry and texture and will determine the color observed by the viewer. The light can when interacting with the object be absorbed, refracted or reflected to various amounts according to the principles of physics. This interaction also determines effects such as shininess, gloss and luster typical of certain compounds. Light, when experiencing a change in media, i.e. air to water, will as a result change the direction of the light waves.iv The light striking the object at an angle, angle of incidence, will be reflected refracted or absorbed. [32] Reflection is often described as light waves being reflected onto a new path while refraction changes the direction of the light waves. [32] Reflection is common of shiny surfaces such as mirrors. The incoming light is shown on to the surface at an angle, and known as the angle of incidence. The angle of incidence is calculated from the normal of the surface (perpendicular to the surface). The angle at which the light wave leaves the surface have the same value. Mathematically speaking this means that θi = θr. Absorption occurs when no light is reflected and is a common feature of pigments and dyes. When all light is absorbed it is seen as the color black. Lastly the light may be refracted, in which the change in medium results in a change of speed of the wave front and its direction. The waves are thus “bent” as their direction changes. The angle of
iv In optics light is often described with the terms light waves and wave fronts. When a stone is dropped into a body of water circular waves are formed spreading in an outward motion. These circles are known as wave fronts and the radial direction in which it is travelling in is known as rays.
Figure 2 A geometric representation of light being reflected. [1]
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incidence and the exiting wave front are thus different and related to each other with the aid of Snell’s law and each medium’s refractive index. From these definitions four primary types of light wave distributions have been found to occur and are defined as follows:
-‐ Specular reflection (gloss) – all the reflected light moves in the same direction.[32]
-‐ Diffusely reflected (scattered) – the reflected light moves in different directions.
Figure 2 Images representing the difference between specular and diffuse reflection. [11]
Figure 2 A geometric representation of light being refracted.[2]
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-‐ Diffuse transmission – Light while leaving an object’s surface is dispersed in all directions. [32]
-‐ Regular transmission – light passing through an object is to a great extent undisturbed but the color is altered. [32]
From these light distributions humans are able to achieve specific properties on surfaces depending on the way compounds scatter the light shone on them. For instance, metallic finishes are obtained by the addition of gold, brass or silver, depending on the desired finish. Their specular reflectance is the color of the metal, this same affect can be achieved by the incorporation of aluminium or mika flakes in paint formulations. This creates a change in color when the viewing angle or illumination angle is changed. When this metallic finish reflects light to a greater extent in certain directions than others, common for automotive finishes, it is described as luster. The change in luster is also desired in the cosmetics industry and is achieved through the addition of pearlescent finishes such as mica.
1.4.3 The third factor of color perception – The human observer The innermost layer of the human eye contains two types of visual receptors, rods and cones. There are three types of cones each sensitive to different wavelengths. The blue cones are sensitive to the short wavelengths, while the green and red cones are sensitive to the medium and longer wavelengths respectively. The second type of visual receptor, rod, is used during septic vision. The rods and cones transform the images seen to chemical energies that stimulate the nerve endings. The nerve impulses are transferred to the brain by the optic nerve where the signals are interpreted.[17]
Some individuals are unable to view certain colors; this is common of those suffering from color blindness. This group is not alone in having difficulties perceiving colors; there are certain factors that can affect every human being’s vision. These factors include the color of the environment surrounding the color that a human is looking at known as the surround color. When colors are close in value and chroma they will seem
Figure 2 Geometric representation of diffuse and regular transmission.
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to change known as the chameleon effect, and the eye can adapt, whereby it changes its sensitivity to a wide range of viewing conditions.
1.4.4 Color Communication As shown through the previous sections, color perception among humans is subjective and describing the color perceived between humans can be quite difficult. In order to facilitate this Albert Munsell created the Munsell Color Order system, the first color order system, in the beginning of the 20th century. It was designed as a method to specify and show the relationships among colors using the three attributes: hue, value and chroma. [17] The system is now used worldwide within the industrial sector when communicating color. It is an effective system that arranges color in a three-‐dimensional space, but like any language the basis must be mastered.
1.4.4.1 The first attribute in Color Communication – Hue Hue is defined by the Terms and Definitions Committee as the attribute of color whereby it is recognized as being predominantly red, green, blue, yellow, violet, brown, Bordeaux etc. [29] Red, yellow, green, blue and purple are the principle hues and placed at equal intervals around a circle. They were each assigned a scale number between 0 – 100, where red has the number 0.
1.4.4.2 The second attribute in Color Communication – Value The value indicates the lightness of a color, and it’s middle point, the color neutral, grey, is located in the centre of the circle. The scale is placed along an axis that is perpendicular to the hue circle. At the very ends of the axis, one can find pure black, below the surface of the hue circle, and above it the pure white. In between these two colors, one can find the greys, which are known as the neutral colors. [17]
1.4.4.3 The third attribute in Color Communication -‐ Chroma Chroma is perhaps the most complex term in the Munsell Color System as it is defined as the degree of departure of a color from the neutral color of the same value. [17] This scale can be described as the colors seen when travelling along the radius of the value circle. Per definition colors of low chroma are said to be weak where as high chroma colors are highly saturated, strong or vivid. When the three attributes are arranged in a three dimensional space it is known as the Munsell Color Space. The hue can be found on the end points of the circle, the value is found perpendicular to the plane while the chroma is found when traveling either inwards or outwards from the center of the circle. According to the Munsell notation the three attributes are noted: H V/C, neutral colors are simply denoted NV/, as neutral colors have no chroma.[17]
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1.4.4.4 Metamerism The color perceived by the viewer is significantly dependent on the 2 other factors in the color-‐perception system, when one of these is altered so is the color perceived. One of the most common perceived color alterations is metamerism and occurs due to a change in the spectral composition of the light by which it (the object) is viewed. [28] In other words, two colors may appear to be the same when viewed under a certain light source but will appear different under another.
1.5 Color Communication within the industrial sector Taking into account the difficulties when determining color, standards have been set in order to eliminate confusion that may arise when replicating color or producing color. These standards have been set using the three factors of color perception system; the light source, the object and the observer, where each has been quantified and adapted in order to be measured by adequate means.[17] These standards have been set by the Commission Internationale de l’Eclairage (CIE) as a means of describing colors with numerical values rather than with words.
1.5.1.1 Standard illuminants – The Light Source Quantified In order to characterize a certain light source, the Spectral Power Distribution (SPD), is used. The SPD is a curve that is characteristic of a light source and is seen as a valuable tool when determining how well a light source renders or distorts color. [17]
Figure 2The Munsell Color System. The circle red, green, and yellow is the hue. The value is located in the middle of the circle and in the radial directions one can find the chroma. [36]
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The most common light source, and the most preferred, is Daylight 65 (D65) it contains the entire spectrum in close equal amounts. This daylight can be achieved by artificial means, through filtering a tungsten halogen source.
1.5.1.2 Standard Objects – The Object Quantified As mentioned in the Object section, the color viewed from an object is a direct consequence of its light distribution. This distribution is measured with the aid of a spectrophotometer, which measures the reflectance, or transmittance of light by an object at a particular wavelength in the spectrum. [29] This is presented in the form of a spectral reflectance curve in which the reflectance and absorption properties are plotted against the visible spectrum. This is recognized as the fingerprint for a color and used to differentiate between colors and measure them.
1.5.1.3 Standard Observers – The Observer Quantified The term standard observer can simply be described as the angle at which the object is viewed.[17] When the CIE was founded the standard observer angle was set at two degrees. This meant that looking at a screen, the viewing angle would stretch two degrees above and below the middle point. This angle was later on increased from 2 degrees to 10 degrees.[17]
1.5.1.4 The CIELab notation and the CIELCh notation The CIELab notation is one of the most commonly used notations when describing colors.v The L* denotes the lightness and darkness of the color, a value of zero is equal to black and the highest value, 100, is denoted as white. a* corresponds to the redness/greenness of the color a positive value is assigned for redness while negative values are assigned to greens.[17] Lastly, b* values determine the yellowness/blueness of the color where yellow colors have positive values and blue have negative values.[17] This scheme is used within cosmetics when describing color and shades as well as other areas such as the painting industry.
1.5.1.5 Expressing Color Differences Once a successful color notation was established, a need for describing the difference in color found between two samples was necessary. This was developed by the Society of Dyers and Colorists and resulted in the CMC, a color difference equation providing a numeric value, between the two samples. It is based on the lightness, chroma, and hue of a color and represents the volume of the acceptance ellipsoid around the standard. [17]
v Closely related to this notation is the CIELCh, which unlike the CIELab values use polar coordinates to express color rather than rectangular values, used by the CIELab notation.
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This can be seen in image 6 presented below. It is now used to determine the pass or fail limit when color-‐matching; a passing value is found within the ellipsoid.
1.6 Color-‐matching foundations The act of color-‐matching is an important aspect within the color cosmetic industry and can be a long and complicated process. Color-‐matching has been defined by the Terms and Definitions Committee as a process by which the amount of each coloring matter present in a material is adjusted so that the final color resembles that of a given sample as closely as possible. [29] When color-‐matching foundations one tries to achieve the color of a benchmark, sample. It can be used for the quality control of shade colors when scaled up to a larger batch size. The main instruments when color-‐matching are the color analyst’s eyes as well as a color assessment cabinet. This is a cabinet fitted with several light settings as well as having monochromatic wall colors. There are two criteria that are taken into consideration when color-‐matching foundations; firstly, the color of the bulk as well as the color when applied on the skin. The process of color-‐matching consists of the colorist placing equal amounts of the benchmark on the forearm, as this is the part of the arm that is not exploited to sunlight. The sample and standard are placed diagonally from one another forming a rectangle as seen in figure 12 and spread out in the same manner. After the foundations are allowed to dry, the arm is placed in a light box where the colorist views the samples underneath D65 (Daylight 65) lighting from different angles to decide whether or not the shades match.
Figure 2 The CIELab coordinates in a color – matching software. The ellipsoid represents the ΔE of which the passing values must be within. The black dot correspons to the standard and the pink dots are samples. The samples are being matched to the standard. [36]
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This method is to a great extent time consuming and recent attempts have been made in order to find a more time efficient method of color-‐matching whereby drawing inspiration from other industrial areas where color-‐analysis is of huge importance using instruments such as spectrophotometers in combination with color appropriate software.
1.7 Investigating the possibility of digitalizing the process of color – matching with color-‐appropriate software
In 1974 Ray K. Winey stated in his article Computer Color Matching with the Aid of Visual Techniques that a spectrophotometer-‐computer combination is an effective tool for helping a colorist to produce acceptable color matches to standards of unknown colorant composition. [34] Similar approaches, relying on a spectrophotometer-‐computer combination, have been taken by other industries dealing with color and color-‐ matching to standards set by marketing or the customer. In these cases the color is matched according to a spetrophotometric method in which the reflectance spectra of the target and the sample are matched as stated in Colour matching by principal component analysis-based spectrophotomeric technique. [25] Spectrophotometers are widely used within the cosmetics industry to assess the optical properties of cosmetic formulations. [9] As this equipment is readily available on the market, it was decided by Oriflame to investigate the method of color-‐matching, utilizing such equipment.
Figure 2 A schematic picture over the color-matching process on the forearm and to the right traditional color assessment cabinet. [36]
[33]
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2 Aim of the thesis The aim of this thesis is to set up a foundation colorant file for the purpose of color-‐matching foundations, with a view to improving the efficiency of the current foundation color-‐matching process in the future. In order to achieve this the following processes were carried out:
• Confirm a sample presentation method to the spectrophotometer • File set up and process • Color-‐matching process • Color-‐matching comparison
3 Definitions and Terms B.O.M – Bill of Materials, a document that contains all the materials needed when manufacturing a foundation. Benchmark – synonym for standard Blender – a monochromatic foundation, a foundation containing only one pigment color, i.e., red, yellow, black, brown and white. Color Computer – term to describe the computer containing the Color iMatch software and to which the spectrophotometer is connected to. The color computer is used for color-‐matching. Drawdown – paint or foundation is applied at a constant speed on a substrate forming a film of uniform film thickness. Drawdowns are a practical way to prepare samples that represent the true color, gloss and appearance of a colored emulsion.[22] ΔE – a numerical value describing the difference between two colors. Note that it is only the difference expressed and not in which way the two colors differ. Illuminant D65 – mathematical representation of average north sky daylight. Mix – a mixture of two or more blenders. Pass/ fail – a numerical ΔE value expressing whether or not a color difference can be seen. Sample – general name used to describe a blender, mix or foundation.
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4 Experimental Part The experimental part of the thesis was divided into the four processes as stated in Section 2. Each of the four processes entailed its own different parts, all of which are presented in the following sections as well as the factors that arose and were needed to be taken into consideration. All of the four processes were dependent on each other and the success of each was an important factor for the overall success of the experiment.
4.1 Confirming a sample presentation method to the spectrophotometer In order to set-‐up a colorant file successfully all of the reference points, as well as samples for color matching were required to be entered on the same substrate. Since the spectrophotometer is quite heavy and has a flat surface the decision was made to use Leneta 3NT – 4 Regular Bond Printing Ink Drawdown Chart as the substrates, hereafter referred to as leneta paper. This would ensure accurate measurements as well as a constant substrate color. Choosing to use a human arm as a substrate would bring challenges with regard to changes in skin color as a result of season. Secondly a change in perceived color occurs as a result of applied pressure to the skin. In keeping the substrate constant consistent results will be achieved through out the color-‐matching process. Further to this, parameters such as the amount of sample used, the application speed at which the samples were applied to the leneta sheet, drying time, and drying conditions were determined.
4.1.1 Instrumentation The drawdowns of all foundations were made using a 1137 Sheen Automatic Film applicator with a Sheen Bird Applicator, producing a wet film with a thickness of 50-‐60 µm. All drawdowns were applied to Leneta 3NT – 4 Regular Bond Printing Ink Drawdown chart.
4.1.2 Method
Figure 2 From the left to the right: The 1137 Sheen Automatic Film Applicator, Sheen Bird Applicator and Leneta 3NT – 4 Regular Bond Printing Ink Drawdown chart. [15] [30] [31]
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The first parameter investigated was the amount of sample used; this was determined by viewing the amount of excess sample left on the bird applicator and runway at the end of each draw down. Once this parameter was decided upon the other parameters were in turn determined. The full report is featured in Appendix 1 (Confidential).
4.1.3 Results The outcome of these experiments, featured in Appendix 1 (Confidential), was for 2 ml of foundation to be applied with a speed of 100 mm/s and allowed to dry for 45 minutes at the Laboratory room temperature.
4.2 Colorant File Set-‐up and Process Once the preparatory work of deciding a sample presentation method to the spectrophotometer had been carried out the set-‐up of the colorant file could begin. The process of the set-‐up of the colorant file was divided into three entities; blender manufacture, mix manufacture and entering the mixes into the colorant file according to the established colorant file set-‐up method. A total of 35 mixes were produced containing the five main blenders white, black, yellow, red and brown in various amounts. These mixes served as reference points for the Color iMatch software and were based on previous work in which the average pigment amount of each pigment in foundation shades ranging from light to dark had been investigated. The mixes were entered into the colorant file and saved according to the set-‐up method.
4.2.1 Blender Manufacture
4.2.1.1 Instrumentation The blenders were manufactured with the aid of a Silverson L4RT, used when milling the pigments, and an IKA RW20 Digital Overhead stirrer, during the creation of the emulsion.
Figure 2 The Silverson L4RT miller and IKA RW20 Digital Overhead stirrer. [27] [35]
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4.2.1.2 Method The blenders were made using the Age Defying Foundation base with a 6% pigment level. The red, yellow, black and brown blenders were manufactured at the bench by the author as per Work Instruction and Bill of Materials, found in Appendix 2 & 3 (Confidential) respectively. The white blender was manufactured in the pilot plant.
4.2.2 Mix Manufacture
4.2.2.1 Instrumentation The mixes were prepared with the use of a scale, in order to ensure the correct amount of blender used as well as a silicone spatula.
4.2.2.2 Method The mixes featured in Table 1 were manufactured at the bench by the author. Each blender quantity was carefully measured into a beaker before being meticulously stirred by the author. The mix was then transferred into a glass jar in order to be kept in storage; five 2 ml samples were taken in order to perform drawdowns according to the method from the previous process.
4.2.3 The Set – Up of a Colorant File and Entering the Mixes Into the Colorant File
4.2.3.1 Instrumentation All mixes were entered into the colorant file with the aid of an Xrite Spectrophotometer SP64 (Figure 15) and saved to the colorant file set-‐up with the aid of the Color iMatch software.
Figure 2 The Xrite SP64 Spectrophotometer. [18
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Table 1 Table of the 35 mixes to be entered into the colorant file.
Mix number Ti02 (%) BLACK (%) RED OXIDE (%) YELLOW OXIDE (%) BROWN OXIDE (%)
1 100,00 0,00 N/A N/A N/A 2 99,98 0,02 N/A N/A N/A 3 99,95 0,05 N/A N/A N/A 4 99,75 0,25 N/A N/A N/A 5 99,30 0,70 N/A N/A N/A 6 98,50 1,50 N/A N/A N/A 7 97,00 3,00 N/A N/A N/A 8 99,90 0,00 0,10 N/A N/A 9 99,75 0,00 0,25 N/A N/A 10 99,30 0,00 0,70 N/A N/A 11 98,50 0,00 1,50 N/A N/A 12 95,00 0,00 5,00 N/A N/A 13 85,00 0,00 15,00 N/A N/A 14 75,00 0,00 25,00 N/A N/A 15 60,00 0,00 40,00 N/A N/A 16 97,00 0,20 2,80 N/A N/A 17 99,90 0,00 N/A 0,1 N/A 18 99,75 0,00 N/A 0,25 N/A 19 99,30 0,00 N/A 0,7 N/A 20 98,50 0,00 N/A 1,5 N/A 21 95,00 0,00 N/A 5 N/A 22 90,00 0,00 N/A 10,00 N/A 23 85,00 0,00 N/A 15,00 N/A 24 75,00 0,00 N/A 25,00 N/A 25 60,00 0,00 N/A 40,00 N/A 26 97,00 0,20 N/A 2,80 N/A 27 99,90 N/A N/A N/A 0,10 28 99,75 N/A N/A N/A 0,25 29 99,30 N/A N/A N/A 0,70 30 98,50 N/A N/A N/A 1,50 31 95,00 N/A N/A N/A 5,00 32 85 N/A N/A N/A 15,00 33 75 N/A N/A N/A 25,00 34 60 N/A N/A N/A 40,00 35 97 0,2 N/A N/A 2,80
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The Color iMatch software developed by Xrite is based on the Multiflux mathematical model, which is a modified version of the Kubelka-‐Munk theory developed in 1931. The theory was developed in order to describe the color of colored materials within the paint and color industry. [23] The theory was later modified in order to take into account other parameters affecting the reflected color rather than the scattering and absorption. In the Kubelka-‐Munk theory, a colored layer of a pigment mixture with a thickness of U is divided into an infinite amount of smaller segments with a thickness of du. In comparison to the diameter of the pigment particles, du, is large. According to the theory when a light is shone onto the colored layer there are two diffuse light fluxes; one downward (i) and one upward (j).[5] The amount of the downward flux when passing through du is decreased by absorption, K, and also by scattering, S. The scattering action, belonging to the upward flux (j), reverses the direction of some of the downward light rays.[5] The higher the concentration of the pigments, the greater the amount of scattering will occur. The theory has taken several assumptions in order to simplify the system in which the colored pigment’s ability to scatter light and the resin’s effect on the final appearance of the color amongst others have been excluded. One of the greatest drawbacks of the Kubelka-‐Munk theory was the disappointing values, the reflected color measurements were quite unsatisfactory when compared to empirical values. In order to improve the reflectance measurements the multi flux mathematical model was developed in which several light fluxes, interactions between the pigment and light source, were taken into consideration. These considerations included the diameter and density of the pigment as well as the breaking index of the resin. Furthermore, the angle at which the color was viewed was also included into the equation. This equation as well as the schematic set-‐up of the system is shown below.
Figure 2 A colored pigment mixture layer with a thickness of U. [5]
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f(K,S,BC,MC) + Rsurface = Rcolor
K = absorption S = scattering BC = 2 boundary conditions of a color layer MC = measurement condition of the instrument
4.2.3.2 Method All mixes were, after they had been drawn down, entered into the colorant file with the spectrophotometer as determined in Section 4.1. In conjunction to the spectrophotometer the Color iMatch software was used in which the Age Defying colorant file was set-‐up with the software by the author. Detailed instructions of this step can be found in the work instruction set up by the author To set up a foundation colorant file using the color iMatch software, Appendix 4 (Confidential).
4.2.4 Results All blenders and mixes were successfully manufactured. However, during the set – up of the colorant file while entering the mixes streaks of the darker pigments; red, brown and black, occurred. The streaks, an example shown in figure 18 found within the oval.
Figure 2 A schematic drawing of the colored layer in the Multiflux Mathematical Model. [37]
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Streaks of pigments had never been encountered before at Oriflame and thus an investigation was launched in order to determine its cause. The streaking indicated that the pigments of the darker blenders were not fully dispersed in the emulsion system. This would affect the measurements taken with the spectrophotometer and in effect also the efficiency of the colorant file. Figure 19, showed that the black pigments were not fully dispersed when the black blender was viewed underneath the microscope.
Figure 2 A drawdown of a mix containing 98.5 % white blender and 1. 5% black blender.
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Both magnifications show that the pigment particle sizes varied throughout the sample as well as the existence of quite large agglomerations of the black pigments. The circular purple dots are water bubbles and the specks of different colors through out the samples are believed to be mica crystals. The decision was therefore made to remanufacture the black blender; however, this time with constant stirring during the milling process in order to obtain a more homogeneous dispersion of the black pigments as well as a smaller particle size. When the new black blender was viewed underneath the microscope the particle size of the pigments in the new black blender had decreased as seen in Figure 20. In order to ensure that the pigments had been fully dispersed after the remaking of the black blender, a new mix, containing 1.5% black blender and 98.5% white blender was produced and then drawn down with the bird applicator machine. Despite the improved stirring during the milling process streaks occurred. The results from this showed that the particle size of the black pigments had decreased, as shown in the images below, however despite the improved particle sizes there were still streaks shown on the drawdown.
Figure 2 To the left a 100x magnification of the black blender and to the right a 400x magnification of the black blender. The large black agglomerations represent the undispersed black pigment, in the image to the left one large agglomeration can be seen above a somewhat smaller body of agglomerations. In the image to the right one can see a continuous array of black agglomerations in various sizes.
Figure 2 A 400x microscopic view of the newly made black blender.
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It now became clear that 8 minutes of milling was an inadequate amount of time and thus an attempt was made to monitor the particle size of the pigments by observing the dispersion underneath the microscope during a prolonged duration of the milling process. This method would show the effect of the increased milling time on the particle size. In between the microscopic viewings the dispersion was placed on a hotplate in order to maintain the temperature. The images below show the evolution of the particle sizes with regard to the extended pigment milling time.
After 14 minutes, the particle size was deemed ample and the blender was manufactured. The microscopic image of the blender showed a decreased particle size. Yet despite the prolonged milling period the mix made showed streaking when drawn down with the applicator bird machine.
Figure 2 From the top left: 400x magnification of the black pigments in the silicone phase after 8 minutes of milling. A 400x magnification of the black pigments after 10 minutes of milling. 400x microscopic view of the black pigments in the silicone phase after 12 minutes of milling. 400x microscopic view of the black pigments in the silicone phase after 14 minutes of milling.
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This demonstrated that 14 minutes of milling was insufficient in order to fully disperse the black iron oxide into the silicone phase. A further investigation of the milling time was necessary. Focus was placed on the other two blenders; brown and red in order to resolve the undispersed pigments as drawdowns of mixes containing these blenders also showed streaks of undispersed pigments. Building on the findings when investigating the milling time of the black blender, the incorporation of the red iron oxide and brown iron oxide duration was investigated from a minimum of 14 minutes. The images of the pigment dispersions in the silicone phase for these two blenders, brown and red, can be found in Appendix 5 (Confidential). Since this milling times were extended to such great lengths compared to the directions given in the Work Instruction for the Age Defying Foundation, as well as never having
Figure 2 400x microscopic view of the black blender made with 14 minutes of milling.
Figure 2 A drawdown of a mix containing 98.5% white blender and 1.5% black blender with a milling time of 14 minutes.
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previously been encountered before, an explanation to this was sought and found regarding the specific densities of the three pigments; brown iron oxide, red iron oxide and black iron oxide. The MSDS sheets for each pigment color showed that the specific gravities for the three pigments varied in size and the larger the specific gravity the greater the milling time required in order to insure their complete dispersion suggesting that the specific gravity of the pigments should be taken into consideration when setting the milling time for monochromatic blenders. These specific gravity values as well the final milling time for each pigment can be found in the table below. Table 2 The specific gravity and milling time of each pigment.
The blenders made with the milling times featured in Table 2 showed an improved pigment particle size and dispersion as seen in the images below for the brown and black blender.
In the above images, there is a more uniform particle size of the pigments and they are continuously spread out throughout the emulsion. Once the pigment dispersions for each of the three darker pigments had been resolved the 35 mixes could be successfully entered into the colorant file.
Pigment Specific Gravity (g/cm3) Milling time (minutes) Brown Iron Oxide 4.6 24 Red Iron Oxide 4.6 32 Black Iron Oxide 4.95 35
Figure 2 From the left: 400x magnification of the brown blender. 400x magnification of the black blender.
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4.3 Color–Matching Process with the Color iMatch Software After successfully setting up the colorant file, the color-‐matching process with the aid of the Color iMatch software could begin. The color-‐matching process with the use of the software entailed a visual assessment by the color analyst as the final product will be viewed by the human eye. In order to measure its success certain factors were taken into consideration. These factors included the choice of substrate, matching according to bulk tone or matching according to the application tone. The difference in substrate, leneta paper and human skin, would lead to a difference in the drying process of the foundation. However, as the foundation will be applied to the skin a color-‐match must always be obtained on the skin according to the current visual method in order to deem the color-‐match successful. Secondly, a consideration was taken as to whether both the bulk tone and application to be matched or simply one of the two. Yet again, it was decided that since the foundations would be applied to the skin by the consumer a color-‐match according to application tone. Color-‐matching to the bulk tone was secondary. Last but not least, the color analyst’s perception of the shade and visual color-‐matching on the skin was the final decision maker when deeming that a shade had been successfully color-‐matched. A method of color-‐matching with Color iMatch software and colorant file was created and the proposed matches were thus fabricated.
4.3.1 Instrumentation The Color iMatch software was used in order to store all standards, proposed color matches as well as to conduct all color-‐matches. The Xrite spectrophotometer was used to enter all standards and proposed matches. The proposed matches were manufactured with the aid of a scale in order to weigh out the required amounts of each blender and mixed by the author with a silicone spatula.
4.3.2 Method The color-‐matching method with the use of the Color iMatch software was established before the color-‐matching process could begin. This process can be found in full in Appendix 6 (Confidential), the method consisted of entering and storing a standard into the colorant file and allowing the software to propose a match recipe with the aid of the reference points. The proposed match would then be manufactured at the bench and entered into the software and stored appropriately. A comparison between the two would be made and a new proposed match would be made if deemed necessary by the software. Two benchmarks, a light and a dark shade, were selected and entered into the database for color-‐matching. In order to determine the success of the colorant file, three parameters were set with regards to the amount of corrections performed; number of proposed matches and the pass/ fail tolerance level with regards to ΔE.
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It was determined that no more than two corrections, three proposed matches, be made to each shade when color-‐matching a shade. The colorant file must work for all shades and that the pass/ fail tolerance level be set at a ΔE of 0.3, in other words the maximum difference between the benchmark and sample be no higher than 0.3.
Figure 3 The Quality Control Window in the Color iMatch software. [36]
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Figure 4 The Formulation Window in which the first suggested formulation is created.[36]
Figure 5 The Correction Window in which each suggested formulation is entered into and measured. All values are given with respect to the standard; all corrected formulations are given as well.[36]
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4.3.3 Challenges When Color-‐Matching with the Color iMatch Software During the course of the color-‐matching session with the Color iMatch software certain challenges were faced. One of the first challenges that arose was color-‐matching the darker benchmark secondly, there was a conflict between the results when visually color-‐matching and color-‐matching with the software.
4.3.3.1 Difficulties in Matching the Darker Shades When the color-‐matching process began, the lighter benchmark Concealer High Def OB Alt 10 here on known as SO 19005, gave good results, while the dark shade Concealer High Def OB Alt 10 here on known as SO 19023 gave unsatisfactory results.vi The suggested shade formulations were far too yellow in comparison to the standard as well as being far outside the pass/ fail tolerance level of 0.3. Below are the two color-‐matching sessions for each of the shades on the Color iMatch software.
vi Despite the fact that OB High Definition Concealer is not part of the Age Defying Foundation it was selected for color-‐matching as the interest in the project was to determine the ability of the colorant file to color-‐match according to the shade of the benchmark. It must be noted that, color analysts receive benchmarks where the formulation of the foundation is different and is required to color-‐match with another formulation.
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Figure 5 The results of the first color-matching session of the light shade 19005. [36]
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As seen in the results from the two previous color-‐matching sessions, the color-‐matching session for the lighter shade was successful; after two corrections the sample was well within the passing ΔE of 0.3 while the darker shade was 0.3 units off (Trial 6 had a ΔE= 0.61) after a total of 5 corrections. This suggested that the colorant file was
Figure 5 The results from the first color-matching session of the dark shade 19023. [36]
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unable to color-‐match the dark shade, SO 19023, successfully and thus two new benchmarks were chosen, in order to verify that the colorant file was unable to color – match dark shades. The two new benchmarks chosen were: Age Defying Foundation GG Natural Beige (321623) and Age Defying Foundation GG Dark Porcelain (321627). The new color-‐matching session for the darker shade 321627 gave the following results: Table 3 Table showing the blender quantities for each suggestion as well as the results from the visual assessment and color – matching session with the Color iMatch software.
Number of suggestion formulation
Blender quantities (grams)
Observations from color – matching on skin ΔE
1 White: 0.48 Yellow: 76.95 Brown: 22.5
The sample is more yellow compared to the standard. More
brown must be added. 8.61
2
White: 0.38 Red: 0.07
Yellow: 60.26 Brown: 39.29
The sample is yet again more yellow in comparison with the standard. More brown must be
added.
4.4
3
White: 2.61 Black: 2.57 Red: 22.09 Yellow: 44.03 Brown: 28.7
The sample is far too bright and red. More white and a hint of
brown is needed. 3.08
Yet again, the suggestions were far too yellow in comparison to the standard signifying that the colorant file was detecting large amounts of yellow in the darker shades. Furthermore the observation was made that the darker the shade chosen the more outside the pass/fail tolerance level the samples were. This posed a question with regards to the colorant strengths of the yellow and red blenders.
4.3.3.2 Conflict of Result Between Visual Assessment and Results From the Color iMatch Software
In certain cases, there was a conflict of result between the drawn-‐down sample and the application on the skin. In other words, the sample when drawn down on the leneta paper and measured with the spectrophotometer, was deemed as a close match according to the software; however when applied to the skin it did not match at all. This is best shown in figure 30.
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From the drawdowns one can see that the first match, Match 1, is redder in comparison to the standard. It can also be seen that the second match, Match 2, is closer in color to the standard than Match 1. However, when these were applied to the skin, Match 1 was a better match to the standard than Match 2. Match 1 is slightly redder than the standard when applied to the skin, as previously seen on the draw down. In comparison Match 2 when compared to the standard was yellower and not as close a match as that between the standard and Match 1.
Figure 5 from left to right: 1) Match 1 ΔE = 2.17 2) Standard 3) Match 2 ΔE = 2.28
Figure 5 The color – matching session of Match 1 and Match 2 on a color analyst’s arm. The sketches indicate where the standard and match have been placed on the photographs. [7]
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The challenges faced when color-‐matching with the software lead to a series of questions concerning the efficiency of the colorant file. The first question that was posed concerned the success of the software to color-‐match a lighter dark shade, in other words a medium shade. This would be done in order to determine if the colorant file was unable to color-‐match all shades that were darker than a light shade or just dark shades. Secondly, the pass/fail tolerance level was examined and investigated whether or not it should be widened. Lastly, the question was posed whether or not the color analyst should be allowed to “tweak” the formulation in order to achieve a passable match.
4.3.4 Resolving the Challenges
4.3.4.1 Changing the Colorant Strength of the Yellow and Red Blenders In resolving the issue of the yellow and red blenders it was recommended by Rafiq Mulla at Xrite to change the colorant strength of the yellow and red blenders in order to determine the change in suggested formulations. Changing the colorant strengths of both the red and yellow blenders was investigated and showed the reverse effects; the suggested formulations had an even greater amount of yellow blender than before the colorant strengths were altered.vii This proved that changing the colorant strength was not the desired solution, attention was therefore placed on the mix quantity and the percentages of the colored blenders; red, yellow, brown and black.
4.3.4.2 Adding More Mixes Containing Higher Percentages of the Colored Blenders It was noticed that the highest quantity of any color with white was 40% thus the software was using these values as a platform when calculating shades requiring higher percentages.viii It was therefore necessary to add mixes containing higher percentages of the colored blenders with white as well as black as the software was unable to correctly calculate the amount of absorption of the colored blender.ix The absorption of the colored blender is calculated by mixing the colored blenders with black.x The total amount of additional blenders added can be seen in the table below:
vii A detailed table over the suggested blender quantities for the suggested shade formulations can be found in Appendix 7 (Confidential=. viii The software is able to interpolate values for percentages of blenders based on in putted percentages, thus in theory the reflectance for a mix containing 60% white and 40% red would be more accurately calculated if there were measurements of 30% red and 70% white and 50% red and 50% white. ix Colored blender refers to the red, yellow, and brown blenders. x As stated by Rafiq Mulla during a telephone conversation on the 28th of January 2011.
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Table 4 The newly entered mixes as well as the corresponding percentages of the blenders.
The colorant file now consisted of 43 mixes, the results when color-‐matching the dark shade 321627 with the modified colorant file are presented below.
Mix nr Red (%) Black (%) Yellow (%) Brown (%) White (%) 36 10 0 0 0 90 37 0 0 0 10 90 38 95 5 0 0 0 39 0 5 95 0 0 40 0 5 0 95 0 41 10 0.5 0 0 89.5 42 0 0.5 10 0 89.5 43 0 0.5 0 10 89.5
Figure 5 The results from the color -matching session as seen in the Color iMatch window [36]
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Table 5 Table displaying the amount of each blender from each suggested formulation as well as their assessment when color – matched visually.
With the new color-‐matching session of the dark shade, the amount of yellow had significantly decreased and the lowest noted ΔE in any of the color-‐matching sessions was noted at 0.97. However, the targeted ΔE = 0.3 had still not been achieved and when conferring with Rafiq Mulla more mixes were added. The new mixes consisted of higher percentages of the colored blenders, mixed with black as well as higher percentages of black blender mixed with the white blender. The addition of new mixes would yet again narrow the distance in percentage amounts of the blenders mixed with white and black in order to ensure a better reflectance and absorption calculation of the software. Further to this, an expansion of the pass/fail tolerance level was made and adjusted to 0.6 as this was commonly used within the industry.xi Table 6 Table showing the new mixes and blender percentages.
The result from this color-‐matching session based on a colorant file with 49 mixes showed promising results. These results are shown in the figures below as well as the table with the amount of each blender and comments from the visual assessment.
xi As stated in email conversation with Rafiq Mulla
Suggestion White Black Red Yellow Brown Visual assessment
1 33.56 0 0 37.53 28.91 Standard is more brown, sample is more yellow. When comparing bulk tone, sample is more yellow/white.
2 29.48 0 5.94 33.47 31.10 Bulk tone: sample is too bright. Sample needs more white & brown.
Mix nr White (%) Black (%) Red (%) Yellow (%) Brown (%) 44 90 10 0 0 0 45 65 35 0 0 0 46 40 60 0 0 0 47 0 1 99 0 0 48 0 1 0 99 0 49 0 1 0 0 99
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Table 7 Table showing the blender quantities for each suggested formulation as well as the comments from the visual assessment.
Suggestion White Black Yellow Red Brown Visual assessment
1 33 3.03 33.86 0 30.11 Most successful first suggestion yet of this shade! The sample is more white and yellower. Add more brown, less
yellow. 2 33.72 1.38 31.96 4.43 28.51 Very close but sample needs more brown
3 33.72 1.38 31.96 4.43 28.51 The software predicted the same suggestion.
Figure 5 The results from the color – matching session of 321627.[36]
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4.3.4.3 Setting a Minimum Amount of White Blender Quantity Allowed for Each Shade Formulation
The B.O.M’s for the Age Defying Foundation shades showed that the white pigment quantity for the dark shades was lower than in the light shade.xii The darkest shade had a white pigment amount of 33% and thus the amount of white to be suggested was set between 34-‐100 %. This lead to further improved suggestions, however, in one case the suggested shade formulation was deemed whiter in comparison to the standard.
4.3.4.4 Adding More Mixes to Bridge the Gap Between the Higher and Lower Percentages of the Mixes
Assuming that the software would be able to color-‐match a medium shade successfully based on the fact that it was lighter than a dark shade was a naïve assumption. After the first suggested formulation was manufactured, similar remarks to that noticed of the dark shades was observed; the formulations were too yellow and too bright.xiii These suggestions were made with a colorant file consisting of 35 mixes. With the addition of more mixes, when resolving the challenge of color-‐matching the dark shade, the suggested formulations for the medium shade improved as well. The first additional 8 mixes to the colorant file lead to improved results; the ΔE for the first suggested formulations decreased by a large amount. The results as well as comments from the visual assessment can be found in the figures below. xii The BOM’s can be found in Appendix 8 (Confidential= xiii The detailed observations as well as suggested formulations can be found in Appendix 9. (Confidential). Please note that these observations were made before any additional mixes were made to the colorant file.
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Color-‐matching session with the colorant file consisting of 43 mixes
Table 8 The suggested formulation quantities and comments from the visual assessment.
Suggestion White Black Red Yellow Brown Visual assessment 1 65.82 0.86 0 20.12 13.20 Close first look on skin 2 63.22 0.83 0.51 21.63 13.81 Not manufactured
An improvement had been made and with the addition of another six mixes further improvements were seen, the ΔE of the first suggestion was yet again lowered and the visual assessment showed passable matches.
Figure 5 Color – matching results for 321625.[36]
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Color-‐matching session with the colorant file consisting of 48 mixes
Table 9 The suggested formulation quantities and comments from the visual assessment.
Suggestion White Black Yellow Red Brown Visual assessment 1 67.40 0.9 18.08 0 13.62 Very close, passable color.
2 63.42 1.01 22.13 0.52 12.92 Good match, however, one of the samples appeared to not match
with the other four. 3 63.37 1.02 21.78 0.71 13.12 Standard is more white.
Figure 5 The color – matching results of 321625.[36]
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In order to perfect the colorant file in the color-‐matching of medium shades more mixes in the mid percentage range, i.e., between the two extremities of the low and high percentage mixes of the colored blenders with the white blender were added. Therefore three final mixes were added, increasing the amount of mixes in the colorant file to a total of 52. The percentages of these mixes are presented below: Table 10 The last three added mixes.
Mix nr Black (%) White (%) Yellow (%) Red(%) Brown (%) 50 0 35 0 65 0 51 0 35 0 0 65 52 0 35 65 0 0
4.3.5 Results The results from the color-‐matching session with the aid of the spectrophotometer showed that with the use of additional mixes the colorant file was able to color-‐match well. The tolerance level was increased from 0.3 to 0.6. This was viewed as acceptable as samples within this range were deemed a close match when assessed visually.
4.4 Color–Matching Comparison The last step, and perhaps the most important step when verifying the success of the colorant file was reproducing one of the suggested matches from dry pigments. In doing so, the colorant file’s ability to color-‐match from proposed matches with the aid of blenders and dry pigments would be verified. This is an important step as all foundations in larger scales are only produced from dry pigments.
As stated when color matching with the aid of the colorant file, the color analyst’s visual assessment would be the final judgment whether or not the color was successfully color – matched. Further to this, the sample when measured into the color computer must be within the pass/fail tolerance level for the standard.
4.4.1 Method The best color-‐matched samples (the ones with the lowest pass/fail tolerance level) were selected and the Color iMatch software calculated the dry pigment content. The raw materials and pigment quantities were weighed out and then manufactured according to the Age Defying Work Instruction.
4.4.2 Results The initial results showed that the foundation shade made from both dry pigments and blenders, when color-‐matched with the aid of the colorant file, was well within the pass/fail tolerance level. It was also deemed as a perfect match when visually assessed. However, as only one shade has been manufactured from dry pigments and blenders it
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is therefore impossible to state that all shades manufactured from both blenders and dry pigments match up. This must be further investigated and seen as a future investigation in order to determine the success of the developed spectrophotometeric method.
5 Results from the four processes The results show that the colorant file and method of color-‐matching with the Color iMatch software was successfully established, after an addition of 18 mixes had been made.xiv The initial pass/fail tolerance level was expanded from 0.3 to 0.7, as color-‐matching sessions with these ΔE values were a good match when visually assessed. Three shades, a light, medium and dark shade of GG Age Defying foundation were successfully color-‐matched. All three were matched according to the software as well as when visually assessed by the author and when asked by members of the color team at Oriflame R&D. Lastly, the results show that the lead-‐time for color-‐matching a shade can be decreased by as much as 66.6 % based on the assumption that it takes an average of 2-‐3 days per shade when color-‐matching with the current method in comparison to 1 day with the use of the Age Defying Colorant file.xv
xiv The work instructions for these two parts can be found in Appendix 3 & 4 (Confidential xv This is based on information provided by Emily Mc Gee, Senior Formulation Chemist.
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Table 11 The final 52 mixes and corresponding blender percentages entered into the Age Defying Colorant file. The abrevation OX stands for Oxide.
Mix Nr Ti02 (%) BLACK OX(%) RED OX(%) YELLOW OX(%) BROWN OX (%) 2 99,98 0,02 N/A N/A N/A 3 99,95 0,05 N/A N/A N/A 4 99,75 0,25 N/A N/A N/A 5 99,30 0,70 N/A N/A N/A 6 98,50 1,50 N/A N/A N/A 7 97,00 3,00 N/A N/A N/A 8 99,90 0,00 0,10 N/A N/A 9 99,75 0,00 0,25 N/A N/A
10 99,30 0,00 0,70 N/A N/A 11 98,50 0,00 1,50 N/A N/A
12 95,00 0,00 5,00 N/A N/A 13 85,00 0,00 15,00 N/A N/A 14 75,00 0,00 25,00 N/A N/A 15 60,00 0,00 40,00 N/A N/A 16 97,00 0,20 2,80 N/A N/A 17 99,90 0,00 N/A 0,1 N/A 18 99,75 0,00 N/A 0,25 N/A 19 99,30 0,00 N/A 0,7 N/A 20 98,50 0,00 N/A 1,5 N/A 21 95,00 0,00 N/A 5 N/A 22 90,00 0,00 N/A 10,00 N/A 23 85,00 0,00 N/A 15,00 N/A
24 75,00 0,00 N/A 25,00 N/A 25 60,00 0,00 N/A 40,00 N/A 26 97,00 0,20 N/A 2,80 N/A 27 99,90 0,00 N/A 0,00 0,10 28 99,75 0,00 N/A 0,00 0,25 29 99,30 0,00 N/A 0,00 0,70 30 98,50 0,00 N/A 0,00 1,50 31 95,00 0,00 N/A 0,00 5,00 32 85 0 N/A 0 15,00 33 75 0 N/A 0 25,00 34 60 0 N/A 0 40,00 35 97 0,2 N/A 0 2,80 36 90 0 10,00 0 0,00 37 90 0 0,00 0 10,00 38 0 5 95,00 0 0,00 39 0 5 0,00 0 95,00 41 0 5 0,00 95 0,00 41 89,5 0,5 10,00 0 0,00 42 89,5 0,5 0,00 0 10,00 43 89,5 0,5 0,00 10 0,00 44 90 10 0,00 0 0,00 45 65 35 0,00 0 0,00 46 40 60 0,00 0 0,00 47 0 1 99,00 0 0,00 48 0 1 0,00 99 0,00 49 0 1 0,00 0 99,00 50 35 0 65,00 0 0,00 51 35 0 0,00 0 65,00 52 35 0 0,00 65 0,00
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Figure 5 Results from the succesful color-matching of 321623. [36]
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Figure 5 Results from the successful color-matching of ure 321625.[36]
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Figure 5 Results from the successful color-matching of 321627.[36]
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6 Conclusions from the Four Processes The conclusion from this project is that the use of a digital colorant file is an excellent tool when color-‐matching foundations as the lead-‐time can be decreased by a predicted percentage of 66.6%. Secondly, there are external factors such as the pigment content of the benchmark and formulation base of the sample as well that can affect the efficiency of the colorant file. A difference in pigment level will affect the coverage of the foundation and in effect the color observed. When these cases occur, the colorist must be allowed to “tweak” the formulation so as to achieve a good match. In other words to alter the color based on the visual assessment of the color. Each foundation formulation requires its own colorant file in order to be successfully color-‐matched according to the method set-‐up. When the color analyst is unsure of the appropriate colorant file to use particularly in the case when given a benchmark with an unknown formulation to color-‐match, the color analyst must apply his or her own knowledge in order to choose the appropriate colorant file.
7 Future Investigations The current work was focused on enhancing the color-‐matching method in order to achieve shades for water-‐in-‐silicone foundation containing a six percent pigment level. This thesis has lead to the improvement of the current color-‐matching method and highlights the fact that one shade can be obtained through different combinations. This was a first attempt in “digitalizing” the color-‐matching method and although the method of color-‐matching has been improved there are further improvements that can be carried out. These improvements are related to the further improving the pigment particle size of the foundations, colorant file itself, the substrate used as well as the formulations. The first challenge that arose during the set-‐up of the colorant file was the streaking of the denser pigments. This indicated that the pigments were not fully dispersed, and that there were quite large agglomerations. A method in order to reduce this would be to use a fineness of grind in which a small quantity is taken and spread over a wedge shaped indent of a grindometer from the deepest to the shallowest part.[16] During the presentation to the Oriflame Color Team and NPD team of this diploma work, several questions were asked concerning the pigment particle size. It appears that Oriflame has previously placed their attention on the amount of milling time in order to determine when the particle size of the pigments were adequate. No emphasis was placed on achieving a certain particle size in order to ensure that the pigments were fully dispersed. The colorant file at the moment color-‐matches well. It is able to color-‐match a shade after three matches, however, the amount of matches before a passable shade is obtained can be reduced. In an ideal situation the amount of matches would be reduced to one or two, this would be done by the addition of further mixes into the colorant file. Suggested mixes include mixes in which the colored blenders, red, yellow, brown and black are mixed together with varied percentages.
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As the initial results from the color-‐matching comparison showed, a foundation shade made from both dry pigments and blenders was well within the pass/fail tolerance level when color-‐matched with the aid of the colorant file. However, as only one shade was choosen further investigations must be made in order to verify that all shades when color-‐matched with dry pigments and blenders achieve the same results. Lastly, the current substrate used requires a drying time of 45 minutes in order for the foundation samples to dry. Research could be focused on replacing the currently used substrate with a thicker drawdown chart.
8 Acknowledgements I would like to give a big thank you to Michelle Allen, Senior Color Analyst at Oriflame for all the support and guidance throughout this project. I would also like to thank Rafiq Mulla at Xrite for his help during the set – up of the colorant file as well as with the process of color – matching with the iMatch software. Thanks a million!
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