HERO ARTS-Clear Stamps: Operation Write Home Collection. Operation Write Home is an organization that supports our nations; armed forces by sending them blank homemade greeting cards to write home on; as well as cards of gratitude to encourage them. Hero Arts will donate 25% of the profits from the sale of this collection of cling stamps to their cause. Each of these clear stamps is made of PolyClear and will stick to any acrylic block. Simply apply your favorite ink and stamp crisp clear images! Available in a variety of designs (each sold separately). This package contains Winter Wishes: a set of ten clear stamps on a 6x4 inch backing sheet. Made in USA.