• Tempera Blocks contain brilliant, opaque nontoxic tempera paint • Simply wet with water to use • For a bright, velvety texture, brush on any surface (even glass) • When colors are mixed directly on the blocks, simply rinse with water for a fresh new surface of pure color • Each tempera block is 2-1/4 in diameter x 7/8 thick • One tempera block will cover more surface than a pint of liquid tempera paint • Holding tray is made of plastic