These clear designer stamps are made of high quality photopolymer. They have a microscopically porous surface which gives superior ink transfer with all types of ink! Ready to use with any clear acrylic block (sold separately).MEASUREMENT REFERENCE: This set comes on a 4 x4 acetate sheet. The Rakhi stamp is apx 2.85 wide and 2.5 tall. The small motif in the middle is apx 3.2" dia.