These canvases are stapled on the back, and excess canvas is folded on back for future re mounting... Deep.Green Label canvases are acrylic titanium primed for use with oil or acrylic painting and double primed with green label 100% pure linen pre stretched canvas 20 in x 24 in each and acid free smooth ground. These canvases are made of fine, 100% pure, imported linen. They are medium weight green label 100% pure linen pre stretched canvas 18 in x 24 in carton of with a pronounced texture and are 3/4 in.