What do an oil slick, a lava pit, and insect anatomy have in common? It's something called thin-film interference, which is caused by light waves that are reflected by a structurally complex coating. Often called iridescence, this phenomenon causes all of these things to shift colors right before your eyes. It's also the secret behind our amazing Super Illusions Thinking Putty. Named for the creature with the fastest vision in the world, Super Fly Thinking Putty will put your eyes to the test! Shimmering tones of metallic green and black give way to gray and silver, just like the body of a common fly. But look again and you'll see tones of peach, mauve, and pink refracting off of its pearly sheen. Each tin includes 1/5lb. of Super Fly Thinking Putty-a huge handful for tons of fun. Gender: unisex.