Originally Posted by MTS
It's for a paper piecing class, right?
Here's a picture:
http://www.buy.com/prod/add-a-quarte...217369647.html
It also comes in a 6 inch length, which might be easier to deal with depending on the blocks you're making.
It's a fabulous little notion to have, and I use it ALL the time when I'm paper piecing.
You can pp without it, but if your teacher is going to be using it in class for a new technique (to you), you're probably better off having it. I'm sure the shop sells it.
I have several "add a 1/4" as well as the "add 1/8". I think they are indispensible for paper piecing! It helps keeps the seam allowance straight with the little ridge it has and THAT helps your accuracy. If the teacher recommends it - get it. part of what you pay for in a class is the teachers knowledge of not only sewing, but good use of tools. If you don't like her way, you can always go back to yours, but your knowledge and experience will be better.