I am looking for a "ruler" that I once saw Jenny use for HSTs. You laid the tip from diagonal point to diagonal point. There was a slit down the center where you could draw the center line and then draw down both sides of the ruler for your 1/4" seams.

I'm working on HSTs and it's not working out right. My squares don't turn out to be 5" consistently and I'm sure it's because of my 1/4" seam being inaccurate.

Thanks,
Diane