Black Sticky Thumb Adhesive Foam - Sticky Thumb adhesive is acid free and photo safe. This package contains 5 pieces of 425 x 2.25" foam adhesive. Total 275 double-sided foam rounds in a variety of sizes. Foam measures 2mm thick. Great for giving a dimensional look to your paper crafts. WARNING: This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm. Do not mouth or chew. Imported.