Growing up in Philadelphia with a small Bichon poodle—who had her own raincoat—Luca Denegre never imagined he would one day preserve a similar canine parka for posterity. However, this year, the second-year WUDPAC objects major found himself working with a stylish red 1960s dog jacket for his science research project. An art school graduate who had previously worked with outdoor sculptures at the Hirshhorn Museum and with Egyptian sculpture at the Penn Museum, Luca had requested an object made from “nasty plastic”—notoriously unstable materials like PVC—and he got his wish.          

The coat was donated to Winterthur’s plastics study collection by the Chicago History Museum; the staff had deaccessioned the coat because “it was starting to ooze this mysterious liquid,” Luca noted. The small jacket “was oily on the surface, and the lining was quite stained inside. It was also being stored flat, with just some tissue paper in a tray. It wasn’t clear what it was.”

Luca’s first challenge was to identify the object’s different materials so he could clean them safely. After taking a small sample and using Fourier-transform infrared spectroscopy (FTIR), Luca determined that the shiny outer layer was likely PVC, which had begun to ooze plasticizer—a clear sign of degradation. The lining, he discovered, was cellulose acetate, a synthetic textile that required gentle cleaning, and the buttons turned out to be casein formaldehyde, “a type of plastic made from milk proteins…which I had never heard of before,” he says. Luca conducted over 20 spot tests, to determine what solvent was safe for the synthetic textile and would effectively clean it. The coat brightened up, and though it will continue to degrade, he noted, “we can keep it in a cooler environment with less temperature fluctuations, and we hope that will help slow the deterioration.”