Quiltbeagle... Thank you for the link to Plainjanethreads. This is exactly what I was looking for. the prices and quantities are exactly what my former supplier offered... Which leads me to wonder if plainjane happens to have been stocking from Brandy's. I'll look into it, as I will need many packs to teach at a quilting retreat next year.
I've tried cutting template plastic from Joanns, but getting a perfect 60degree diamond is more difficult that you might think. I definitely notice a difference in my points when I use non-laser cut pieces. Paper and yardstick is not as beginner friendly as the mylar. Your needle just glides against the mylar, and it's impossible to sew through, making them reusable forever.