ooh one weird story I have is.. this pair of vinyl (aka plastic polyseter) shorts I had completely fell apart after 10 years in the closet :P The plastic coating fell off the backing material, which is very typical for "vegan leather" type material. I wanted to preserve it cuz it had a sticker (probably also vinyl?) stuck on it by the band I like during a concert. So I guess you'll have some knowledge of vinyl preservation since that's a common material for itabags.

Wonder if you maybe had suggestions for like "fannish clothing" like t-shirts with prints and such?