There is a Very Excellent Explanation for Why the Measuring Tapes Feature Diamonds in their Design.
The great majority of us will, at some time in our lives, either make use of or be witnesses to someone else making use of a measuring tape. Even if you likely missed this minor issue, I will include it in this discussion.
If you look closely, you’ll notice that the tape is marked with extremely small markings intended to assist users in determining the appropriate area in which to put wall studs. If you want to pinpoint the center of two studs, you can use the black diamonds, also known as stud finders.