You can make it yourself by painting canvas painters tarps with linseed oil. Wash the tarp in hot water to close the weave, nail the tarp to the back fence, this is an outside project, and paint it with the linseed oil. You can add color to the linseed oil before you paint it. When it dries, put another coat on til you are happy with the thickness. Let dry between coats. Leave it hanging outside till the smell disperses.