Sprite Editor Texture Tab
From Shoot Em Up Kit
The Texture tab is used to select the texture that the sprite you are creating in the Sprite Editor is on.
Click the texture thumbnail to bring up a list of available textures to choose from. To add a new texture to this list, put it in the My Documents/Shoot-Em-Up Kit Projects/textures folder if it is to be available in all projects, or the My Documents/Shoot-Em-Up Kit Projects/projects/[PROJECT NAME]/textures folder if it is for a single project only.
When you have selected a texture, set the position of the sprite in the Sprite tab.