polyester question
 

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 percent

Some of the nicest sheets that I have ever had were 60/40 - they washed and dried really well and were so soft. But, on a quilt that my aunt made, she used some poly/cotton - don't know the percentage - and it "pilled" a bit - sort of a bumpy feeling. It may have been a higher percentage - maybe even 50/50. I don't think that you will have a problem though. However, if the other sheets that you used were not the same percentage, then you may have a different shrinkage.

I've used whole poly/cotton sheets for backing a couple of times. I wash my quilting fabric as soon as I get it home, so any shrinkage is taken care of before I quilt. Then I wash the quilt when it's finished to check that everything is secure and it looks good after washing.

So far, I've had good luck with the poly/cotton sheets. I also use flannel sheets that I purchase new at end of season sales in Sears. They have to be washed first, but work great, too.

I use sheets all the time, partly because I'm a cheapskate. But if I need some fabric NOW I often resort to using poly/cotton sheets since I live in a small island community that doesn't have much in the way of retail fabric selection. We have Joann's and a small LQS that I can't usually afford. I also wash my fabric before cutting and piecing so any shrinkage has already happened. I have never had any problems mixing cotton and poly/cotton sheets either while making the quilt or afterward. It's a great source of yardage especially on sale! Go for it!

Cotton is just easier to work with. The sky won't fall if you use poly/cotton. Promise! ;) If you are making an heirloom quilt for a quilt show with hundreds of hours into it, you might care more how the different fabrics fade. But, there are no hard and fast rules, it's your quilt, use what you like!

For years I used poly/cotton sheets for backings, as the availablity of extra wide fabrics just didn't exist. In fact we prefered blends , because they did not wrinkle hardly at all. Not all blends will pill. So I say... go forth ... use them.
Interesting I very receintly purchased 100 percent cotton, high thread count sheets...and they pilled!

Thank-you!! I feel much better now. The fabric is white so no fear of fading. I cut the sheet into 10 inch squares and sewed with the others. I had no problems sewing it. This weekend I will hopefully FMQ and bind. I am really hoping I can get it under my sewing machine. I have the Janome 7700 - anyone out there that has the same machine and has done king quilt - I would love some tips...I am going to do a simple meandering since its a revisable quilt.