I�m in agreement with a lot of what was said, and would offer what I was told some time back by a well known blade maker whose company was in business long before WW I. The etching templates were of an acid resistant wax, and he sent me an example which I (may or may not) still have, and the correspondence that is probably filed away somewhere. Being made (from memory) in batches by something like a silk screen process and stored away until needed. With the wax etching mask being applied to a slightly warm blade so that it adheres well, forming a good seal to keep the acid etchant away from the areas that were to be protected.
Followed up by an artisan to correct any defects in the mask application before etching. Which is where the human element comes in. As these were not machine made, but done one at a time by people of different abilities and changing circumstances. FP
