Though it is very densely written in technical chemical terms, this new research article, based on direct analysis of pits punched out of cels in the Walt Disney Archive, may be interesting to collectors who are concerned about the long-term stability of our collection.
Cels tested ranged from Snow White up through the whole range of classic Disney productions, including cel-based art for productions (like Lilo and Stitch) from the 2000-03 era. The gist is that the chemical composition of cel stock varied more widely than anticipated. Disney changed from using cellulose diacetate to cellulose triacetate around 1981, and the types and percentages of plasticizers used is quite different in each type of cel stock. Also, percentage of plasticizers found in all the cels tested declined significantly with age. That suggests that one of the processes at work is that the more volatile compounds tend to evaporate (which, if their impact is to soften plastics, would make the observable puckering of cel bags understandable).
The investigators are working toward gaining knowledge that will help in fine-tuning recommendations for long-term storage, particularly recommended humidity/temperature levels, so collectors will want to keep an eye open for future reports of this team.
