Minecraft wiki entry for Resource_Pack, associated text: The texture files of the default fonts contain a grid of white characters, which are automatically colored by Minecraft as needed in-game. The character sizes are automatically determined based on the last line of pixels containing any alpha value. Due to the way fonts are detected, filling the background of a character with a color containing a 5% alpha background causes the full width to render without generally having a visible background to the character. The default font character is 8×8 pixels, while accented.png is 9×12 pixels.