The problem isn’t skill — it’s visibility.

The human eye starts losing definition around three thousandths of an inch. That’s a 30% margin of error when you’re trying to measure relief at ten thousandths.

In other words —
you literally can’t see what you’re trying to measure. But even if they all matched exactly, there’s a better, quicker way —

There’s a Better Way

Precision doesn’t require expensive tools. It requires a known reference.

String clippings are exact, known diameters — and you already have them.

Bend a short 90° leg and use it as a feeler gauge.

• If it slides freely → gap is larger
• If it just starts to bend → you’re right at the target
• If it won’t fit → gap is too tight

A B string (.011″–.012″) is ideal for checking relief.
A slight bend tells you you’re right in the sweet spot.

And for measurements under .020″ — like nut slot height — string clippings are fast, repeatable, and extremely accurate.

This is just one way how MasterPro removes guesswork — and replaces it with repeatable precision.