I'm not real sure, but I think I used Lucite acrylic. There is no printing on the protective paper cover on the left over piece I have, though there was on the part I used. In its current form, this blade can only coat a 5 1/2" x 15" area. Not very economical if I cut a 6" strip off a standard 22x30 sheet of watercolor paper where I would like to get 3 5x7's.
I have some UHMW plastic in 3/8", it's not very rigid, it is very slippery. If I go the plastic route I need something that can be worked with woodworking tools and not need a special grind on saw blades and drills.