June Tailor slotted ruler
I love mine and use it all the time. I got a cut on one edge of a slot with the rotary cutter and my DH just sanded it a little
and it was like new. I find I cut much straighter with it. Put some sandpaper dots on the four corners and occasionally
throughout the bottom of the ruler and it will help it stay in place. They will fit right in between the slots easily.