the alignment of light.

Mechanical precision can only be verified using references more precise than the tools themselves. In our workshop, we use custom-configured laser collimators to project perfectly straight optical lines across the lengths of our larger slate bed plates.

By measuring the micro-deviation of the projected beam off mirror-finished reference points, we verify absolute flatness down to 100 nanometers. This optical audit reveals microscopic twists and crowning that standard steel straightedges fail to register, guiding the hand-scraper with absolute geometric certainty.