This unprimed canvas is 36" (3 feet) wide.
Single fill ducks differ from numbered ducks in that there is only 1 yarn in the weft. Numbered ducks will have 2 yarns making it stiffer & stronger.
Cotton duck (from Dutch: doek, "linen canvas"), also simply duck, sometimes duck cloth or duck canvas, is a heavy, plain woven cotton fabric. Duck canvas is more tightly woven than plain canvas. Cotton duck is used in a wide range of applications, from sneakers to painting canvases to tents to sandbags.