Well, if you wanna sell the texture item, it's like selling a painting. You buy the frame and then you put a piece of art there. Selling textures is done in the market, while art is sold at the art/textures subfolder at the forums. Remember, as joker said, to not sell art you got free, or if you achieved it in an item duel. Item duels just gives you the frame, unless it's specified you will get the art too. Hope this helped