An SMSKIN file contains a skin used by StarMade, an open-universe space simulation sandbox game. It contains a skin, which is a texture used to customize the appearance of a player. SMSKIN files are created from .PNG files that come default with the game or are customized by a user.

The PNG file that makes up the SMSKIN file can be edited to change a player's head, neck, arms, legs, feet, and body. The image consists of each of the body parts and is wrapped around the player model. You can apply skins to your player by selecting Modding → Custom Skin and navigate to the skin you want to apply to your player. The SMSKIN file is meant to be opened only within StarMade. However, it is compressed in the Zip format, which allows you to manually extract its contents with a utility such as 7-Zip or WinZip. StarMade's allows you to explore the universe finding materials to upgrade your ship and fend off attacks from enemies. In the game you navigate through sectors, which may contain space stations, other ships, asteroids, planets, stars, or nothing at all.