I know that Joann's carry them.
I save various clear plastic lids for this.
I have printed out shapes on file folders cut to fit through my printer.
If it is a template that I am going to use a lot, I use plastic. Each time you trace around cardboard, the template edges shrink. If you hold up the first tracing and compare it to the 20th, you can visually see the difference. Imagine the difference if you cut 100's for a large quilt... So rather than running into a problem when I go to put them together, I just use plastic to begin with :wink: