I've used them and they work really well for making half square triangles for all sorts blocks. There was a shop I frequented that used them for a "buck a block" you got fabric strips and thangles and a different layout each month to make a block, at the end of the year you could have a small quilt. It worked. I 've made a few more on my own since. they come in a variety of sizes. There is another brand that comes on a roll and I like even better if you can find them. The paper is a bit thinner and tears away easier.