When I first got into quilting I saved dryer sheets to use. I used some of them but then discovered there was paper made for foundation piecing and backing applique. I tossed the dryer sheets.

thank you all for your great and informative answers, I will not be using them

OK, have to tell on myself! I also heard of this method, so jumped in with both feet and asked my daughters to sacve their dryer sheets for me so I'd have a good supply before I started. I forgot, they use a different brand and "odor" than I do. I have always used unscented everything in my house! They don't!! Oh my!! The delicious "odors" coming from the bag they sent me. Needless to say, the smell never dissipated and I had to throw them away, I never told my daughters LOL.

Never tried foundation piecing, maybe someday! Good Luck!

I have saved mine and used in foundation piecing. Basically stitch and flip scrap pieces. The brand I used came out to about 5" X 7". They went together beautifully, quilted easily, and the quilt has gone through more washings than I can count. I love it!
I was going to do it for charity quilts but was told that any residual perfume could be bothersome for some children, so I didn't.
I now have 2 grandkids who are bothered by the perfumes in both detergents and softeners of any kind so I no longer use the sheets. I use lavender sachets instead!

I wouldn't use them in a quilt. I'm allergic to things that smell of perfume.

I have used them for applique backing. I think it's a good use to recycle them.

I don't use dryer sheets, but do use the color catchers from the wash. Yes, they have colors, but I try to match them up with the fabric (main color) that I am using. I just give them a light press, and proceed with my piecing. They do not tear well, so I only use them when I want the extra firmness in a quilt [such as a wall hanging] because I leave them in the quilt.

Ditto - the only time I ever used them was to keep mice away. Yuk to that smell.

I know a gal in my quilting club who uses them to make blocks for QOV quilts.