Penny Black Cling Stamp 4"X6". Slapstick Cling Rubber Stamps. Penny Black stamps feature high-quality images in red rubber with a 1/8 inch foam pad for maximum transfer. Stamps are available in a wide variety of themes and designs for every day and every occasion! This package contains Angel of peace: one cling rubber stamp on one 5-1/4x4 inch backing sheet.