Originally Posted by butterflyquilter
What is this?
It's a ruler that has slits in it that your rotary cutter fits into. It's great for making strips of equal width.
Here's a link to what one looks like. You can see the teardrop shapes at the top and bottom of the ruler. You put your rotary cutter into those teardrop shapes and cut.
http://www.quiltingboard.com/t-63070-1.htm