AIC's 45th Annual Meeting

Research is underway at the Getty Conservation Institute (GCI) and the Walt Disney Animation Research Library (ARL) to investigate storage and treatment strategies for animation cels. Animation cels are transparent sheets of cellulose nitrate, cellulose diacetate, -triacetate or polyester that are inked on the front - which is the viewing side - and painted on the reverse. A condition survey of animation cels, selected from productions between 1937 and 1989 from the ARL collection, revealed that only a small percentage of cels show evidence of paint cracking, delamination or flaking. This paper will present recent innovations in paint reattachment, based on research findings, which rely on intrinsic hygroscopic properties of the cel paints. As described in lab notebooks, paint recipes and other documents in the Disney Archives, paints made at the Disney Ink & Paint Department between 1936 and 1986 were formulated with gum-based binding media. Surfactants and humectants were added to the paints to improve application to the plastic sheets and impart flexibility to the dried paints. Verification of the archival information was carried out using gas chromatography/mass spectrometry (GC/MS) on a selection of cel paints, which also provided useful estimates of pigment-to-binder ratios and precise information about additive compositions. Time-lapse video of an experiment, placing a cel in an environmental chamber and fluctuating between 15 and 75 percent relative humidity (%RH), revealed the responsive behavior of the sheet and paint. Surprisingly, previous delaminated paint reattached in some areas at elevated RH levels. To investigate the causes of these phenomena and assess the relative hardness of paints as a function of RH, selective paints were studied using manually applied indentation on a micro-scale ranging from 30-85%RH. Interestingly, some colors became almost fluid above certain %RH levels, but regained their firmness as the RH was reduced. Analysis of these paints by a nano-indenter instrument is planned for comparing to the results of manual indentation. Time-lapse studies of cels undergoing temperature cycling will also be conducted for comparison. Based on these findings, the conservation approach aims to investigate the reactivation of hygroscopic additives in the paint media, thus minimizing the creation of a moisture barrier. A number of application techniques are explored that utilize humidity, solvents and combinations of both, with limits imposed by the solubility parameters of the paints and plastic sheets. Use of a specially constructed workstation based upon approaches for reverse-glass paintings conservation, where the object is elevated onto a glass plate and a mirror is placed underneath, permits simultaneously viewing and imaging the front and reverse of cels during tests and treatments. The use of humidity and solvents to treat flaking paint by reactivation is a balancing act that poses interesting practical and ethical issues. Can treatments cause permanent distortions in the plastic sheets? When can migration of additives in the paints and sheets occur? To what extent can paint be re-solubilized without changing its original characteristics? Responses to these issues will be discussed.