Hero Arts-Clear Stamps By Lia. These clear stamps peel off their backing and stick to any acrylic block making for easy stamping. Simply apply your favorite ink and stamp crisp clear images! They are made from 100% photo-polymer which is latex free, phthalate free, non-toxic and biodegradable. Available in a variety of designs (each sold separately). This package contains Discover: a set of twelve clear stamps on one 6x4 inch backing sheet. Made in USA.