Premium grade, natural, double fill, close weave, unbleached unprimed artist canvas. Ready for priming with either oil or acrylic primers. Excellent for painting with oils, acrylics or alkyds. 100% cotton. 10 oz. (Medium/Heavy Weight). “Fill” refers to the horizontal yarns or those running perpendicular to the selvedge of the fabric. Double Fill means there are two threads to the yarn.