Procedures and Conservation Standards for Museum Collections

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<p>Procedures and conservation -standards museum collections for i transit and on exhibition nNathan Stolow</p> <p>4-r</p> <p>0</p> <p>E :. ( r</p> <p>0Y4</p> <p>0 a J</p> <p>PI</p> <p>E</p> <p>U</p> <p>Protection o the cultural heritage f</p> <p>Technical handbooks for m u s e u m s and m o n u m e n t s</p> <p>3</p> <p>Titles i this series : n</p> <p>T e guarding o h f</p> <p>cultural property</p> <p>by William A. BostickMuseum collection storage by E.Verner Johnson and Joanne C.Horgan Procedures and conseruation standards for museum colleclions in transit and on exhibition by Nathan Stolow</p> <p>Nathan Stolow</p> <p>\</p> <p>Procedures and conservation standards for m u s e u m collections i transit n and on exhibition</p> <p>Published by the United Nations Educational,Scientific and Cultural Organization 7 place de Fontenoy, 75700 Paris Printed by Irnprirneries Populaires de Gentwe</p> <p>ISBN 92-3-101913-90 Unesco 1981Printed i Switzerland n</p> <p>Preface</p> <p>Travelling exhibitions of al kinds are inl creasing a a great rate.The resulting damt o age may be attributed t poor packing and transportation techniques,which are often out-dated,o climatic variations and even t t o incompetence on the part of untrained or partially trained museum personnel. Unesco and ICOM (The International Council of Museums), particularly through its specialized international committees, have over the years sought t reduce the o hazards and risks involved i exchanges of n cultural objects. This work is a condensed version of the authors book entitled Conservation Standards for W o r k s o Art in Transit a n d on Exhibition, f which has already appeared i Unescos n Museums and Monuments Series. This shorter text is being made available i the n TechnicalHandbooksseries,which aims t o give practical and technical guidance on the conservation and restoration of cultural property. Intended t contribute t the internao o tional spread and exchange of professional knowledge and experience, the series is destined i particular for museums and monun ments services whose resources are limited and which must find solutions t their probo lems of conservation that are more suited s t the means available.It i hoped that the o information i this handbook wl succeed i n il n providing practical guidelines i t i sense. n hs1. Nathan Stolow, Conservation Standards for Works Art zn Trans11 and on Exhibition, Paris, 1979.</p> <p>The author is responsible for the choice and the presentation of the facts contained i n t i book and for the opinions expressed hs therein,which are not necessarily those of Unesco and do not commit the Organization.Acknowledgement</p> <p>The author wishes to acknowledge the assistance ofJohn Lavender i the preparation of n</p> <p>the drawings.</p> <p>o f</p> <p>(Museums and Monuments, XVII.) (English and French.)</p> <p>Contents</p> <p>Introduction 9 Deterioration of museum objects 13 Storage of collections 17 Storage devices and equipment 17 Fire control 1 8 Location of store-rooms 1 8 Handling and packaging techniques 21 Damage attributed t human o factors 21 Preparation f r travel and o exhibition 22 Further remarks on handling and movement within the museum 2 6 Packing of works of art and museum objects 28 Transportation 4 1 By road 4 1 By r i 42 al By sea 43 By a r 43 i Remarks on shock and vibration in transport 45 Standards and guidelines for exhibitions and travel 47Appendices 5 1 Select bibliography</p> <p>55</p> <p>Introduction</p> <p>The emphasis i t i work is on promoting n hs standardsof total care and handling of exhibitions a al l v l of activity a al places t l ees t l and a al times.This concept may seem obt l i l vious but many readers w l know from their own experience how e s l damage and deaiy terioration can come about i travelling n exhibitions when s f i i n attention is not ufcet given t even simple conservation and care o procedures. In many instances,exhibition t a f c ocrfi curs without the advance consultation of experts who could ensure that the objects surlvive the rigours of travel and changes of c i l mate.Al too often the conservator is called i only when the object is already damaged n as a result of some unfortunate mishandling i transit or abrupt exposure t a sudden n o change i humidity and temperature. O b n viously, not al works can travel safely,exl cept a great expense. A point is reached t where the cost of transporting certain works s n may be as great a that involved i bringing n t groups t see them i situ a the museum o proper. Conservation science has advanced t a o degree where measures can be instituted t es and hardware designed t resist or a l a t o fet attenuate the e f c s of vibration,shock and climate changesparticularly those of relat v humidity. Such measures enable paintie ings,sculptures, photographs,ethnographic and archaeological materials t be transo ported without risk. A the early planning t n stages, s a f can be trained i appropriate tf handling,packing and shipping techniques. Loan agreements and contracts can be</p> <p>made t specify the technical and consero vation requirements and transit administration for the overall physical safety and security of the collections involved. The author in an article published in Museum referred t the development of a o new type of conservator-an exhibition conservatorwho would be concerned with al the matters of technical and conservation l excare associated with exhibition+from amination and environmental monitoring t advice on handling and packing. Finally o there would be a period of observation after the return of the collection to establish whether the various travels had caused any delayed action: such as the development of cracks,fissures,or l s of adhesion of strucos tural elements. Often there appears t be a conflict beo tween the exhibition organizer on the one hand and the conservator on the other.The former is concerned with having the work viewed i a well-designed setting by as n many people as possible. Impediments t o viewing, e.g. glazing, low l v l of lighting ees and similar conservation measures are often i ignored,or paid lp service to.It is a misconception t say that the conservator wishes t o o cocoon object in such a way that it can the no longer be enjoyed-it is safe but invis-</p> <p>ible !Fortunately there is a middle ground t o be found between the two opposite philosophies. This depends on establishing com1. Recent developments in exhibition conservation,hluseurn, Vol.XXIX,No. 4, 1977.</p> <p>9</p> <p>Procedures and consemation standards for museum collections in transit and on exhibition</p> <p>1 0</p> <p>munication between exhibition organizers and designers on one side,and conservators and like-mindedcurators on the other.Such communication should develop a the cont ceptual stage of the exhibition and not when al the hardware is installed and ready l o t go. It is possible, for example, t design o cases and vitrines which are pleasing to the eye and yet have controlled environments within,or for lighting t be kept t minimal o o levels by avoiding adjacent brightly lit areas. It is also fairly easy to install lamps outside cases rather than within where they become prodangerous sources of heat-ausing found variations i relative humidity apart n from l g t damage t fadeable materials. ih o s o Another simple and obvious measure i t lend objects t museums a times of the year o t when the climates are similar.For travelling exhibitions seasonal disparities and simil r t e between centres can be readily idenaiis t f e and necessary changes in itinerary be iid made. The conservation-care measures i n simple or complex exhibitions, i single n loans, or those involving many items of national treasure status have certain como m o n denominators.T h e obvious one is t o have the object returned t its lender in the o same physical state or extremely close t this. Thus, the structure from the surface downwards should remain unchanged and not exhibit any weakness that might give rise t delayed-action damage. This is no o easy task. Objects of wood, textile, paper, leather,horn,and a variety of humidity-sens t v materials are known t change dimeniie o sions readily according t variations i relao n t v humidity and temperature. The situie ation is more serious where objects are composed of both humidity-sensitiveand inert materials; severe strain can develop with subsequent cracking or breaking. Large paintings on canvas can be subject t vibrao tion e f c s which cause eventual weakening fet</p> <p>of the adhesion between the fabric and the paint-layers proper. Heavy sculptures not properly cushioned have been known t o tess break a points where the s r s e and t shocks have not been properly dissipated. Decorative arts and ethnographic materials im wrapped directly i polyethylene fl have n grown mouldy or mildewy as a result of condensation and high-humidity environments locked i as micro-environments n around the object. It is sometimes thought that ancient objects somehow survive the shocks and ut rigours of movement and travel.This is j s not so. Ancient wooden objects, e.g.from the Tutankhamen treasures, respond qualitati e y i the same manner as seventeenthvl n century furniture,or nineteenth-century Indian masks, when the relative humidity undergoes cyclic changes. The originating museum, or institution, f in asking for proper care o its objects on loan should re-examine its o w n handling and conservation standards. Often these leave much t be desired.A review of the o most basic receiving:shipping, storage, handling, and examination procedures should be periodically carried out. N o institution should be immune from self-scrutiny and aim for improvement.The care of cultural n property starts therefore i the museum itself. H o w the works are handled at the shipping door, moved, stacked, temporarily stored, examined, environmentally conditioned and exhibited-all influencei an inn cremental fashion their f n l condition.T o ia ensure constancy of condition means exercising tender and expert care a al times t l and places.The first place t practice this i o s i the museum proper. n The sections that follow attempt t o compress an extremely broad subject into a manageable and concise form.The coverage starts with the description of causes of de-</p> <p>Zntrodzictiorr</p> <p>terioration of collectionsand suggestions are made for measures t minimize damage;folo lowing this are guidelines for the storage and preparation of objects for exhibition; f concise descriptions o handling and packaging techniques, and of transportation at methods and their evaluation. The l s major section lists current guidelines and standards. A list of useful references and data are appended a the end for further t o study. The illustrations are selected t demonstrate acceptable and safe techniques within the means of both small and largebudget institutions. By extension and modification of the methods shown it is possible t make applications t other fields o o a well. Thus, the method for packing a s three-dimensionalwooden sculpture could be readily applied to an anthropological object or an elaborate piece of decorative art. lt Likewise, the technique of handling f a works, e.g.,paintings or drawings,can be extended t photographic items of various o dimensions and format. The overall purpose of this test is to identify the technical and conservation problems i the preparation and organizn ation of exhibitions,and t show through o examples how conservation care can be maintained.In t i way,it is hoped that the hs reader directly or indirectly involved in t i hs field may be made aware of the need to maintain collections a al phases and t l t venues.It is only by improving standards a al l v l and by their constant implemental ees tion and monitoring that the works of today can survive intact for the enjoyment of future generations.</p> <p>11</p> <p>Deterioration of museum objects</p> <p>Most museum objects are composed entirely,or in part,of materials which respond readily t moisture in the atmosphere,that o is t the relative humidity (RH), exhibit o and dimensional changes, i e expansion when .. the R H increases, contraction (shrinkage) or hs when the RH decreases.In t i category are c l u o i materials: wood, paper, cotton, ellsc el jute,linen,as wl as protein,animal,bird, fish,and insect materials: silk,wool, parchment, leather, fur, feathers, horn, bone (ivory). Most plastics,e.g., nylon,polyester, polyethylene are humidity-insensitive and absorb very little moisture,but often exhibit surface s a i which varies with the ambient ttc RH.Metals do not take up moisture, but can form in the presence of carbon dioxide, sulphur dioxide, chlorine, etc.,oxides, sulphides,and various corrosion products.The t ferrous metals, iron for example. rust a higher l v l of RH.Copper and its alloys, ees bronze and brass,can form carbonates (normal greenish patina), or bronze disease i n the presence of additional chloride airborne contaminants. Silver is notorious for forming dark sulphide deposits. Gold and platinum are theoretically inert. But there are examples of early gold contaminated with base metals reacting to atmospheric pollutants.Stone objects are porous and can o allow moisture t penetrate. Under indoor museum conditions this presents no danger a the dimensional changes are negligible. s However, outdoor exposure a frost-level t conditions can be very damaging,causing ex-foliation and cracking a the surface. t Ceramics and baked clays are more or less</p> <p>i the same category as stone.Ancient glass n objects can respond superficially to R H levels. O n e such phenomenon is known as crizzling, the development of opacity at the surface. Where museum objects are multi-component,e.g.part wood,part metal or, as i n paintings,part pigment ( n r ) part textile, iet, it is obvious that a choice of RH is very d f i u t t make for the entire structure.If ifcl o the object i t i category is already dimenn hs sionally stabilized a a particular level of t RH, it is best to maintain this level at al l times. This is often not the case. Paintings are subject t stresses and strains, panel o paintings and furniture t warpage and o cracks,and ethnographic objects of complex construction to deformation and breakage. Museum files contain much information and documentation which confirm the hazards of environment on the structures and s a i i y of multi-materialobjects. tblt The basic aim of the conservator is to maintain the RH level as constant as poss b e for the simple-construction,moistureil sensitive collections,and arrive a comprot mise l v l for the multi-componentones.A ees possible solution i the l t e category is t n atr o apply moisture-barrier coatings t the hyo groscopic portions, thereby rendering the total object l s susceptible t dimensional es o el o changes. This technique is wl known t painting conservators who have long experimented with vapour barriers on the backs of wood-panelpaintings. The RH should be kept as constant as possible,so as t avoid dimensional changes o</p> <p>13</p> <p>Procedures and con...</p>