If you’re like me, a tape measure is an important tool in your utility drawer or tool box. And one thing my father taught me that I’ll never forget is to always measure twice and cut once. Because once you cut, you can’t undo it. I’m sure you’ve heard the old proverb yourself!

While you’re certainly familiar with the inches and centimeter markings on the tape measure, there is one object that might not be as familiar to you.

But we decided to take it upon ourselves to educate the masses about the mysteries of the tape measure. And one thing we stress is the black diamond you’ll find if you look closely. While people can always just do the math in their head, the visual aid of the diamonds makes it much easier.