Originally Posted by grdmachris
The starch and sizing you put in the fabric will build up on the needle and also gums up the bobbin race in your machine.
Originally Posted by Geri B
I just don't see the reason to "starch til it's like cardboard" in order to piece a quilt.
Starching fabric until it's like cardboard is helpful when you're making a very intricate block or when you've got a lot of bias edges or when you're preparing pieces for turned-edge applique using the starch method.
If you iron your fabric right sides together while it's still damp, it sticks together for rotary cutting and sewing.
Otherwise, normal starch is enough to make your fabric behave.
If you starch your backing fabric, it will slide more easily when you're quilting, and it will do some of the pre-shrinking. :)
I've never had a needle gum up when sewing heavily starched items and I've never seen anything more than the usual oily lint in the bobbin area in any of my machines.