Which is better for preserving old comics, Mylar bags or regular poly bags after I tested both on a 1973 issue of Spider-Man?

I left a copy of Amazing Spider-Man #125 in a Mylar bag and another in a regular poly bag on my shelf for 6 months, and the Mylar one stayed perfectly flat while the poly one started yellowing at the edges, so has anyone else seen a clear winner like that or is it just my luck?

2 comments

2 Comments

matthewsullivan6d ago

Man that poly bag yellowing thing is real. I left a stack of early 70s Daredevils in poly bags for like eight months and the edges on the bottom issues turned that gross yellowish brown, while the Mylar ones I used on a separate run of Cap issues looked crisp as ever. It's nice to see someone else confirm this, I was starting to think my storage closet was cursed lol.

brooke4755d ago

Oh dude, did you check the backs of the books too? I had the same thing happen with a run of old X-Men I bagged in poly sleeves, and the yellowing basically bled through the bag onto the cover staples. It's wild how fast poly breaks down compared to Mylar, even just sitting in a closet. I switched everything over after that, now I only use Mylar for anything from before 1980.