An Artist’s Guide to Color Management - ?· An Artist’s Guide to Color Management What do I need…
Post on 29-Aug-2018
Today, many artists who onceprinted in darkrooms or usedconventional methods ofreproduction have moved to digitalprintmaking. Digital imaging is anintegral component in many artistscreative style. For traditional artists, itis a route to reproducing their work asfine art prints. In both cases, commu-nicating with your printmaker beforeembarking on a project will ensurethe best print possible.
Traditionally, the printmakerwho handles the complete processfrom imaging to final output bestserves artists. But digital creation andprintmaking may not take place atthe same location. Even when theydo, artists need to be able to commu-nicate their vision of the final colorto their printmakers.
There are many questions artistshave about managing color:
What do I do if my original is cre-ated on a computer?
What should I do if the image onmy monitor doesnt match my orig-inal?
How do I know if I can rely on mymonitoror my printmakers mon-itorfor making accurate colorcorrections?
44 DIGITAL FINE ART SUMMER 2001
What an artist needs to know about color management, which allows color to be translatedaccurately from one part of a printing/viewing system to another.
By Dan Reid
An Artists Guide to
What do I need to talk about withmy printmaker so there are no sur-prises when I see my prints?
One of the easiest ways to com-pare color has been on the computerscreen. However, computer monitorsuse RGB (Red, Green, Blue) to createan image while digital printers useCMYK (Cyan, Magenta, Yellow,blacK) to create prints. Unless you areskilled in separating an image intoCMYK for printingand colors dochange when translated from RGB toCMYKyou may be disappointed inthe difference between what you seeon screen and what is printed.
Part of the solution is to use acolor managed workflow. Color man-agement allows you to send an imagein the original color model (usuallyRGB for scanners, cameras, and mostinput devices) to your printmaker andstill maintaining the richest data forconverting to CMYK. Most printmak-ers do this conversion, although somemay request CMYK files.
In Photoshop a traditional sepa-ration model clips over-saturated col-ors while in-gamut colors remainunchanged. This flattens the mostintense colors, resulting in less-than-pleasing prints. Color managementsoftware, through the use of ICC/ICMcolor profiles, can compress or expand
the color gamut proportionally. AnRGB ICC/ICM workflow, for exam-ple, allows the same image file to beadjusted to print on different outputdevices or papers while still achievingsimilar color appearance.
Color Management SystemsColor management systems are avail-able for both Mac and PC operatingsystems. Windows 98 and 2000 andMacintosh 7.1 and higher have theability to translate color using a cross-platform file format.
Instead of ambiguously assigningnumerical values to control reproduc-tion, a color management system reliesupon a color model based on howhumans respond to color. Unfortu-nately, the human eye does not have alinear response to color. People have ahigher sensitivity to certain colors anda lower tolerance for others. Colormanagement factors in these qualitiesas it translates color from one deviceto the next.
Color management, however, isnot a silver bullet that will automati-cally fix image color. A successfulcolor managed workflow is directlyrelated to the controls that are inplace at each imaging device. If adevicescanner, monitor, printercannot be calibrated to correct fornon-linearity or cant verify that a cer-
SUMMER 2001 DIGITAL FINE ART 45
tain standard has been achieved,then color management wont help.If your equipment does not offer cal-ibration, the ICC/ICM color profileof your images will only be good forconditions that exist at that time.
A color management systemencapsulates the color reproductioncharacteristics of each device into across-platform (Mac/PC) file format.An ICC or ICM (PC) file containsa three-dimensional color map of adevices reproduction characteris-tics. This three-dimensional model
Switching papers or printers canhave a radical effect of color per-formance. Notice the variancebetween the different papers print-ed on an Epson 7000 comparedto the ColorSpan DisplayMaker XII.The DisplayMaker can achievemuch more saturated blues, greens,and magentas compared to theEpson 7000 ICC/ICM profiles.
Input devices can have radicallydifferent color gamuts. Large for-mat digital cameras capture alarge range of tones than film scan-ners. So, the BetterLight studiocamera system shows an enormousrange of color on this chart. TheEpson 1600 and Optronics Color-Getter scanners are limited by thefilm's color gamut.
This diagram shows how the human eye responds to different colors, which is not in alinear fashion. When creating ICC/ICM profiles, human color sensitivity is factored intocalculations. Image courtesy of Xrite, Inc.
is perceptually uniform to that of thehuman eye.
RGB and CMYK color modelsare dependent on how each devicerenders color. Without color manage-ment, printing a file on two differenttypes of paper (or printers) results indistinctly different prints. If a file isviewed on two computers with identi-cal monitors, the image may alsoappear differently. This is why bothRGB and CMYK are called device-dependent color models.
Color management software pro-
files or fingerprints imaging devicescolor characteristics. This softwaregenerates color charts that are dis-played on computer screens or areprinted. For input devices, test chartsare scanned or photographed and com-pared to reference data files. The accu-racy of the resulting file is related tothe calibration of the device prior tousing color management software.
Who Is Responsible For Color?If your artwork needs to be pho-tographed for reproduction, consultyour printmaker for the output devicesspecifications beforehand or have yourphotographer ask if you dont under-stand those specs. Including a colorreference chart in a transparency isalso extremely useful. That chartmakes it easy to hone in on the correctcolor balance using white, black, andneutral patches.
If you submit a digital file to aprintmaker, ask what file types andcolor model (RGB or CMYK) thecompany prefers and if it supportsICC/ICM profiles.
CMYK files can be looked uponas limited edition color modelsbecause they are highly specific andare only valid for a single device,paper/ink, and RIP/printer setting. Onthe other hand, submitting a RGB fileto printmaker can provide the richestcolor data, which can be retargeted tovarious printing devices or papers.
Converting to CMYK using anICC profile early on ensures the bestreproduction using a particular device,but if printed with a differentpaper/ink, screening, or RIP setting,the color would most certainly be dif-ferent. Careful readjustment of the filecan help compensate, but it wontachieve the same level of quality.
Reproductions Of ArtWhen reproducing original art, consid-
46 DIGITAL FINE ART SUMMER 2001
er a printmaker or imaging studio thatuses a digital studio camera. A largeformat digital camera can capturemore detail and a wider color palettethan a transparency. Scanning a 4x5chrome is limited by the film grain,which can obscure details at the highmagnification needed for large-formatoutput. Since the final output is froma digital device, acquiring the richestdata with a large format digital camerais a smart approach.
Matching TransparenciesIf your original is on film or has beencopied onto film, ask yourself if youhave the hardware and the skill need-ed to color correct an image for thekind of print you want. Generallyspeaking, transparency filmneeds a scanner with a highoptical resolution and widedynamic range to capturethe films entire colorgamut. Printmakers andimaging houses have scan-ners that offer the bestwork. You can take thesescans home on a disk tocolor correct yourself, oryou can have your print-maker do the work.
If you have a 4x5 trans-parency scanned at a localpre-press shop, be awarethat you will usually be pro-vided with a CMYK fileseparated for offset webpress conditions. The SWOP (Specifi-cations for Web Offset Printing)printing process, inks, and paper areradically different from those used forfine art reproduction.
A better approach would be touse a RGB color model to retain morecolor information. However, it may bedifficult to convince your scanningsupplier to provide a RGB file insteadof CMYK. Ask beforehand if they willscan your chrome in RGB.
ProfileCity has a unique approach to creating andadministrating ICC/ICM color profiles, using the webinstead of having you purchase and learn software.This window shows color gamut plots of differentICC/ICM profiles and which profiles are active or dis-abled on your computer.
Color Management At HomeIf your printmaker provides anICC/ICM profile of its paper and inkcombination, you may be able to getyour desktop printer to simulate theservice provider output. The qualityand look wont be the same, because adesktop printer and media createprints with more saturated color thanfull-size printers do with fine art inksand papers.
Using an equipment companysown coated/glossy photo paper andink can sometimes provide a colorgamut larger than fine art watercolorpapers. If so, color management canadjust the printer to simulate fine artoutput.
Most pre-packaged ICC/ICM
profiles from equipment manufac-turers do not contain enough datato represent varied printing envi-ronments. Humidity and tempera-ture influence how quickly paperabsorbs ink. Your results will vary ifthe ink is absorbed at a differentrate from conditions used to createthe color profile. A custom profilealways provides better color match-ing by taking ambient conditionsinto consideration.
Profiling Packages For Artists There are several profiling packagesavailable for under a $1,000 that pro-duce great ICC/ICM profiles. The keyto creating meaningful profiles is tostandardize your settings and configu-rations. If you inadvertently forget todisable the auto color correction on adevice, then your profiles will beworthless. If a device cannot be set toa calibrated standard each time youuse it, then you will not be able toimplement color management suc-cessfully.
One easy-to-use profiling packageis Monaco EZ-Color (978-749-9944). Its simple interface guidesyou through profiling your monitor,scanner, and printers. For bettermonitor profile accuracy you canadd a colorimeter to measure themonitors performance. Monacouses your scanner to read printertargets. This method works well fordesktop inkjet printers but is notaccurate enough for full-sized fineart printers. Using a colorimeter offers a farmore accurate profile of what yourelooking at. The better the monitorprofile, the more accurate thescreen simulation will be. A col-orimeter attaches to the face of acomputer screen with suction cupsto measure the projected colorpatches.
Praxisoft WiziWYG (703-450-8001) is another profiling applica-tion that can use a scanner or colormeasurement device for readingprinter targets. The WiziWYGpackage is available with colormeasurement hardware in severalbundles. The profiles it creates arevery good. Adding color measure-ment hardware will definitelyimprove the accuracy of your pro-files here, too.
Comparatively speaking, MonacoEZ-Color supports emissive col-orimeters for monitors while Prax-isoft WiziWYG supports reflectivecolorimeters in addition for printerprofiling.
Colorblind Matchbox (858-613-1300), in addition to creating mon-itor, scanner, and printer profiles,can tune or edit a ICC/ICM profileto better hone in on color output.Included is Colorblind Spot, whichcan use your custom profile to cre-ate close simulation of named col-ors (PMS, Trumatch, etc.). Just likePraxisoft and Monaco, Matchbox islimited to 300 color patches, suit-able for desktop inkjet profiling.
Color Vision (609-895-7488)offers Profiler RGB and CMYKproducts that use a scanner forinput. The products work as Photo-shop plug-ins and provide rudimen-tary profile editing tools. TheCMYK product offers control overblack plate generation. The blackink is used to optimize gray balanceand color fidelity.
Profile City (760-436-4149) offersa new approach to controllingcolor. Color is managed by ProfileCity instead of you because it offers
a profiling service over the Inter-net. You can purchase color meas-urement devices that connect tothe company via the Web. ProfileCity has developed a uniqueapproach of tracking device driftstatistically. It also offers good arti-cles and resources on color manage-ment.
Wide Format PrintingLarge/wide format printers invariableprovide more control by using bettersoftware to drive the printer. One ofthe most important considerations,aside from which printer to use, is theRIP (Raster Image Processor), whichcontrols the printer. This is one of themost important factors in achievingsuccess in high-quality output.
ScanVec-Amiable technologies,Wasatch, CadLink, and BestColor alloffer excellent RIPs. These manufac-turers either support or allowICC/ICM profiles to be created. Eachtakes a different approach to colormanagement. Some allow printer pro-files to be loaded but wont acceptdefault ICC source profiles for files
that are not tagged. This is theresult of an important point: colormanagement is dependent on its usein a specific work flow.
The bottom line is that by usingthe tools already available on yourcomputer you can get better repro-duction. Several inexpensive colorprofiling products are available thatcan characterize your imaging devices.Implementing color managementrequires learning how to use theresulting ICC/ICM profiles with yoursoftware and hardware.
While no print will look exactlylike the image you see on a monitor,color management will help youunderstand the difference. With theknowledge you gain from using colormanagement, you can interpret whatyou see on your monitor to achieveprints that are more faithful to theoriginals.
Dan Reid, owner of New Mexico-based
Renaissance Photographic Imaging, helps
companies and artists migrate to color man-
aged workflow. For more, see www.rpimag-
ing.com or e-mail email@example.com.
SUMMER 2001 DIGITAL FINE ART 47
Mac users can point their web brows-er to www.icctools.com to down-load freeware software for viewing ICC
profiles. In Photoshop 5, open the RGB
set-up window (file-color settings/RGB set-
up), and save each RGB editing space to
your ColorSync folder in your system fold-
er. You can view each ICC profile to deter-
mine the smallest gamut RGB color space,
which contains all of the colors of the ICC
printer profiles you intend to use. For Pho-
toshop 6, installation is automatic, with
Profiles and Recommended aliases appear-
ing in the ColorSync folder.
The ColorVision Profiler comes with a colorimeter for measuring monitor color perform-ance. It works with Adobe Photoshop 5.x and higher as a plug-in. Unlike some pack-ages, Profiler RGB/CMYK provide easy control to edit, or tune, an ICC/ICM profile fora particular look. ColorVision also offers a Pro version that supports printer color meas-urement devices.