Skin

A 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, there's the front head area, left leg area, etc.). A skin will only allow solid color; transparency is not allowed on the skin file except on the second head area, which is transparent by default. The second head layer can be used to give the character glasses, hats, or other accessories (even a bigger head).

History
The player skin originally had a beard (that was commonly mistaken for a smile), and was removed in Beta 1.6.6. Though, if you happened to find one of these bearded skins, and stick it in your mob folder in the minecraft.jar, you can see what the old skin clearly looked like.

Exclusive cloaks (later renamed capes) were added in Beta 1.0 on December 20, 2010.

In October 2011, Notch re-named the cloak to the cape mentioning that the name was already wrong in the first place.

So far the Christmas and New Years Capes have only been given out in 2010 and not subsequent years.

As of the 1.9 pre-releases and 1.0.0, all "bottom" textures (including hand and foot) have been flipped 180 degrees. It's worth mentioning that the textures were specifically flipped and not rotated because an updated texture with the bottom surface rotated as opposed to flipped may display incorrectly depending on the intended alignment with relation to the rest of the skin.

World Textures
A skin can also refer to other textures in the game, such as block textures, item sprites, mob skins etc. A list of these can be found here. Modifying these has been officially supported since the Alpha 1.2.2 Update on November 10, 2010.

It is worth noting that Pigmen, Zombie, and Zombie Pigmen mobs can use typical player skins (and vice-versa). Skeleton mobs can use typical player skins as well, but keep in mind that they have their skinny arms and legs. (If a skeleton mob skin is used as a player's skin, their legs and arms will NOT be skinny.)

Changing Player Skins
A player can only change their character's skin if they purchased Minecraft. This is done on the Profile page by uploading a valid .png image file, which will then replace the default skin. The char.png file in minecraft.jar can also be changed and replaced, but then, only in that game will the player character appear different, and anyone else using the default skin will appear to that player to be using the changed skin as well.

You cannot change your skin in the Xbox 360 edition.

Creating a skin


A custom skin is a great way to personalize your player model and can be done either by using a variety of community-made skin editors or by editing Minecraft's char.png file manually. This is stored in the minecraft.jar file and can only be accessed by using an archive decompressor (such as Winzip, Winrar, or 7-Zip).

On Windows, minecraft.jar is located in "C:\Users\User\AppData\Roaming\.minecraft\bin", accessed by pressing + and entering "%appdata%" in the command box.

On a Mac it is in "/Library/Application Support/minecraft/bin"

On Linux it is in.

Skin files must be 64 x 32 pixels.

Capes
Capes (previously known as cloaks) are vanity items and are worn in addition to the player's skin. There is currently no way to obtain a cape on one's own, however there are various mods that allow players to do this.