We have a factory in our town that makes drapes and quilts for motels and such. They give away batting pieces, and have HUGE bags of batting you can buy for $10. The bag is so big I can hardly carry it. One piece of batting I found in there was big enough for 2 king size quilts with some left over. If you don't have access to something like this, do what others have said: Good Will, St. Vinnie"s, Salvation Army, etc.