I have a lot of fabric that I have collected thru the years and I know some of it isn't 100% cotton. Isn't there a test you can do to check to see if it is all cotton?

And if you make a quilt and some of the squares aren't all cotton, what will happen? Why is 100% cotton prefered fabric? Can you make a quilt out of poly-cotton fabric if you pre-wash the fabric?

Thanks in advance. I appreciate all your helpful answers. This has been the best group of people that give great advice.

I've done a burn test. I take a bit of fabric, maybe a 1 x 1 inch square and place a lit match to it. Cotton will burn, 50/50 will melt. Be careful though, don't want to burn the whole stash!! :)

A friend of mine goes to a lot of estate sales. She described to me going in the back somewhere to test fabric out with flame- I don't know how she does it without setting anything else on fire or being discovered!!!

Wrinkle test is good also as long as you're sure it's not silk or rayon. Scrunch it up and see if it wrinkles. It not, it's not 100% cotton, rayon or silk--they all wrinkle.

This is the easiest, quickest, least-likely-to-get-you-arrested test.
Wad a bunch of it up tight and release it. Polyester fibers were invented to prevent wrinkling...you can use that very trait to determine when there is any in a blend.

Also look at the cut edge; blends tend to fray differently, with longer, straighter threads/fibers.

Jan in VA

great info

Glad you asked Elaine! Good recall for me.
Maureen

Thank-you all for your help. I have to go thru it this weekend to see if I have enough to make some boy quilts and I was a little worried about mixing the two fabrics. I will try the wrinkle first. Wouldn't want to burn the stash up!

I have mixed poly-cotton blends and 100% cotton fabrics in quilts with no ill effects (and one of these is a quilt for my son that has been washed 4 or 5 times now). As long as you prewash, everything should be fine.

Good advice and technique. Would hate to be arrested for "testing fabric" (rofl).