Hi Margaret, a Blotter Sheet (Item 1632) is a large sheet of blotting paper to place under your picture whilst painting. It absorbs the paint that goes through the non-woven material and protects your tabletop. It makes painting easier as it provides a firm yet absorbent base. You can use both sides of the blotting paper, many times, as the paint dries and you can continue to paint more pictures. We sell them in a set of 2 sheets. Regards Jenny