The only ScaleMode I know of is related to the GUI system. There is nothing like it for a GUITexture. But you are in total control of your GUITexture scaling. Setup the GUITexture.pixelInset values to represent the actual size of the bitmap then make sure any scaling of the texture at runtime to either the pixelInset or to localScale is done 1:1. Note if the aspect of your background does not match the aspect of your image, then you will need to either stretch or clip.