Loopy Hues are made from unique materials to ensure their longevity. Kids love coloring with Loopy Hues because they don t leave residue on their hands, are odor-free and never need sharpening! Loopy Hues Triangular and Round crayons are super bendable. Our 3D Number and Letter crayons are so durable, but not bendable...yes, we wish they were too! They are great for children learning their numbers and letters.