What would the charity receiving the donation do? Turn it down, I don't think so. Seriously, charity quilts can be made out of any fabric, preferably fabric on hand, that needs to be used up. Our guild will happily take any quilt that is donated. I don't waste my time sewing of fabric you can see through, but I have found some awfully good deals on good fabric. All you have to do is keep your eyes open and look around. Our LQS has a flat fold table, and I find pieces there that I have paid $10 a yard for 1.99 - 2.50 a yard. If it passes my touch test, I buy it.