The best backdrop I ever owned bought, or made is the one I happened to make. I bought a painters canvas drop cloth. I managed to get a piece 10' by 12' from it without any seems. I made a rectangular form from 1x2 strips with triangular corner braces. Then I laid it on the ground. With a real natural sponge and three different colors of paint I began mixing the colors on a board. I sponged it with about a hundred overlapping circles until there was no visible pattern. It was a sort of mottled grey when unlit. Depending on the strength and placement of the back light it would be light or dark. It could have white highlight or black highlights even dabs of red now and then. It was never a dull backdrop. I have it rolled up now in a corner of my deserted studio. I saw the article on muslin so I thought I would give you a different version. The good thing about painted canvas. If you dont like it, just take it outside and add more paint. I never did mine was good on the first try. A friend of mine used matress ticking to do the same thing. Matter of fact I helped him paint it.