Originally Posted by
OzarksGma
The poly blend fabrics will have a hard ball where it was burned and the cotton will have a white/gray ash.
The hard ball is the plastic from the poly, which may give off black smoke.
OzarksGma
Other things to consider: Often the frayed threads around the edges of a cotton/poly blend are thinner than the same threads on an all cotton piece of fabric. I also prewash and when ironing, use the hottest setting on the iron (cotton or linen), which is too hot for a cotton/poly blend, so the cotton/poly blend will give off a light pungent odor. 100% cotton never smells like that---it only smells clean or like nothing at all. You can also shine a blacklight over the fabric, because polyester will glow in the blacklight, cotton will not.
