Because Polyguard's specially formulated polypropylene has a physical density that is less than other sleeving materials, it's more pliable and gentle to your film...and it floats!

TRY THE POLYGUARD FLOAT TEST
Simply cut out a small sample of sleeeving, then completely submerge it in a bowl of water. Make sure no little air bubbles attach to the plastic.

Polyguard archival sleeving will float to the top every time. On the other hand, vinyl, acetate and other lesser quality sleeving will sink to the bottom.