Key to success seems to be getting things absolutely clean right down to the bottom of the line and having sufficient depth of line to work with.
Rules in particular seem to pick up a surprising amount of crud over the years which can be hard to shift. Job for a retired toothbrush and decent solvent I've found. But check the handle in the solvent first. Way back I had one try to dissolve!
Never found anything that worked on the shallow lines found on some relatively modern equipment. Martins comment about black-it and skim makes me wonder if thats the sort of process used on modern shallow lines. The dials on my S&B 1024 show no evidene of actually being etched in the first place. Just thin black lines.
Clive
Edited By Clive Foster on 18/10/2020 13:07:25
Edited By Clive Foster on 18/10/2020 13:07:50