Minecraft wiki entry for Skin, associated text: A custom skin is a way to personalize the player model and can be done either by using a variety of community-made skin editors, or by editing the steve.png or alex.png file manually with an image editor like Photoshop, GIMP, Paint.net or similar image editors. The steve.png file can be downloaded here and the alex.png file here. When editing the steve.png or alex.png file manually, be sure to keep the original image dimensions and make the background of the skin (the unused pixels) completely transparent. Otherwise, Minecraft may fail to recognize the skin as intended.