Butterfly wings have a layer of tiny scales. These scales contain many special chemical pigment particles. These colorful pigment particles combine to form colorful patterns on butterfly wings. In addition, there are many horizontal ridges on the scales. The more ridges, the more patterns on butterfly wings. Although the color of chemical pigments on these scales is magnificent, the color will gradually fade or disappear due to oxidation. Therefore, sometimes we can see that only a transparent film is left in a part of the butterfly’s wings.