I don't see why not especially for a charity quilt. I actually back my charity quits with muslin to save $$$

Just not a fan of poly, and hate working with it. Have you run out of cotton? I would donate it and be done with it.

I have been known to use some poly, especially if the colors are right. My grandmother mixed double knit, poly, and cotton, and hers are still doing just fine.

I think it would be just fine to use poly/poly blend. I wouldn’t buy it, but I would certainly use it if I had some available, especially on a charity quilt. I think it’s actually sturdier than 100% cotton.

Thanks for the question and answers. I had some pink polyester in a give-away bag, but had pulled it out hoping I could use it in a charity quilt somehow. Now I will!