Pen size (although listed as "Pen-s" on the menu) is a tool in Powder Game, Powder Game 2, and Earth Editor that determines how much of an element is created on the game screen when the element is placed. Left-clicking on the pen-s button increases the pen size while right-clicking decreases it. There are a maximum of nine pen-s settings. The number keys can also be used as a shortcut for changing the pen size.