Claybord's ultra-smooth finish, rigid hardboard back and the absorbency of the kaolin clay make it an exceptional surface for pencil, ink, acrylic, gouache, egg tempera, plus multimedia uses. Colors remain true and brilliant on this surface. It is unique because areas of your art can be completely reworked over and over without ruining the integrity of the surface. Scratch it with a knife or gradually remove color with steel wool to add contrast, texture and fine details. Exceptionally lightfast. The mineral-coated, white surface is pH neutral and acid-free. Boards measure 5x7" and 1/8" thick. 3 boards per package.