Photopolymer is a magical material which can be effectively “engraved” with a combination of your art, UV light and a chemical bath. It is frequently used to print digitally-set type and art using a letterpress, and just like other letterpress-printable media must be mounted type high on wood or metal (such as honeycomb). Gerald Lange, educator and proprietor of the Bieler Press (and a good friend of Hrant Papazian) wrote an excellent book on using photopolymer, by far the best reference work on the subject.