Blue Rose Mounting Strips consist of two sheets of oriented polystrene foil welded together along one edge (Hawid style). The foil has a crystal clear front with a Jet Black Back. The Giant size has a split back design, sealed on both the top and bottom edges (Showgard style). The foil is completely safe for stamps, will not shrink or discolor, and is 100% waterproof. Pre-gummed on the entire back. Moisten the bottom half lightly.