I made a king quilt this weekend...and for the backing I went to goodwill and found three brand new sheets. One was white and it was in the package but it did not say what it was made of...I got it home and it was 40 percentpolyester and 60 cotton. I debated on using it...I decided to, I used all three cut them in to 10 inch squaures. I had no problem sewing it...why is it that quilters do not use it?? it really seems like its good quality and not issues cutting and sewing it...will I have problems when I wash it? I plan on FMG'ing the quilt so it should stay in place. I pray there is no issues using it since this quilt is huge and hope this is my last King size quilt...I made it double sided so its two quilts in one.