Minecraft wiki entry for 2010_Indie_of_the_Year_Awards, associated text: Skin refers to the texture that is placed onto a player model or mob. The skin is divided into areas that act as the surface area of the character (for example, the front head area, left leg area, etc.). A skin allows only solid color; transparency is not allowed on the skin file except on the second layer, which is transparent by default; playing offline, pixels can be left free resulting in "holes" in the skin. The second layer can be used to give the character glasses, hats, or other accessories. Players can also change the arm size to be slim or normal. The slim variant is 3 pixels wide while the normal variant is 4 pixels wide.