Under The Sea Stamps - Art and Craft Supplies (12 Pack) Under The Sea Stamps. Our foam stamps are specially designed with children in mind! Theyre lightweight and easy-to-grasp in simple kid-friendly designs. Theres so much kids can do with these stamps  create cards, stationery, posters, gift wrap, illustrate an essay, make decorations and so much more! Color an ocean scene with these 12 easy grip stamps. 3" - 4"