Well the polyester has proven to be easier to clean and as thinner leaves less fold lines up th sides of my pressed cheeses when used in cheese molds. But it is a woven material and un-seamed like cotton but unlike cotton it more easily has long thread runners coming off of it that are a pain. Was a good idea, does not work well.
So I went to Wal-Mart supply store again and found a package of cheesecloth, wow that stuff is thin - gauze like, no wonder DD just throws it away, agree, too difficult to wash and USD4 for 6 square yards / 5 square meters.
Also, off of a bolt-roll, I bought some medium weave Nylon Tulle at USD1 per square yard, similar to the polyester in that monofilament but heat melded together rather than just woven, so it will not run like the polyester or cotton. Like the cotton cheesecloth in the picture, it is very course and thin and thus would be good for lining hoops for cheese pressing but not for hanging curds to gravity drain whey as not strong enough.