Double knit poly is a hard fabric to work with as it is slippery so I wouldn't use it for a quilt. I made a rag quilt with some that my mother gave me to use and she had cut all the squares and such, but if I had done a big X in the middle of the squares, then they might have been better. But it is a slippry fabric so it would probely be better for making clothing out of. Ejoy your new stash. I'd have a ball going through all that fabric. Huggies, Fay