This MasterPieces 18" x 24" 500 piece Hidden Image Glow-in-the-Dark Puzzles features secret pieces which glow-in-the-dark, and others that hide in plain sight. Artist, Steve Read hides amazing hidden images within each beautiful piece of art, and his puzzles never disappoint. Find all the secrets in these wildly entertaining puzzles! To reduce their impact on our environment, the chipboard used in these puzzles is made of recycled material.