Susan,

I believe your concern is valid with a PU base material. AFAIK Mylar has a higher sticky point temperature than PU.

If that turns out to be the case, I suggest taking the sheet out, dusting it with talc on both sides (or possibly corn starch), and re-folding it for storage. Remember to close eyes and stop inhaling momentarily when shaking it out. (Any old rocketeer knows what I'm writing about).

Regards,

Tom