I found a way to have very small rulers. I am a model railroad nut as well as a dedicated wood worker. I try many times to measure very small spaces. I was at a hobby shop and bought an inexpensive X-Acto® knife, kept the blade for my other stuff, and got a small stainless steel ruler and cut it into 6 pieces from 1/8″, 1/4″, 1/2″, 3/4″, 1″, and 2″. The X-Acto knife came in a plastic tube which is perfect for keeping it all together.