October Afternoon clear stamps are made of photopolymer resin. This high-quality material gives the stamps their strong "cling" and excellent ink carrying characteristics. For improved customer satisfaction, October Afternoon clear stamps are made of non-yellowing photopolymer.
As with all October Afternoon stamps, these are made in the USA.
For general size reference, the 'DO NOT BEND' stamp (middle near top) is 1-1/4 x 1/4 inches and the 'this book belongs to (middle left) is 1-1/2 x 3/4 inches.