I would think about pencil lines.
I’ve noticed a word popping up in the media. Granularity. It means the quality of resembling small grains or particles but refers more specifically to the practice of viewing something in greater detail, or at a higher resolution or with greater granularity.
It doesn’t take much granularity to see that a pencil line has three elements:
1. One edge
2. The other edge
3. The space between the edges where all the graphite is.
You take your measurement, transfer the point on the tape measure to the piece of wood with a pencil mark, or what carpenter’s call a “crow’s foot”, which is actually TWO pencil marks converging on a point. Then you draw another line through the point you think is the exact place the crow’s foot converges. By the time you set the saw against the wood to make your cut you have accumulated a number of opportunities to stray from your original measurement.