Looking for the superior clarity of polyester in a sheet that lies flat in a screwpost book? Look no further than Pina Zangaro's flex-hinge sheet protectors.
These 100% archival sheets are much clearer than polypropylene, and they lie perfectly flat thanks to a hinged binding edge.
Made of archival-grade DuPont polyester (polyethylene), they're available in three formats and are sold in packs of ten.