What is the best way to darken etched graduations on older steel rules?—Al Saffron
Steve Costain replies: If the etchings are deep enough, you might be able to fill them with a paint stick. McMaster Carr has “Paint Markers for Recessed Characters” at www.mcmaster.com and then search for “2018T2”. Their description…“Rub the marker over the recessed surface and wipe off excess paint while still wet. The oil and wax-based lacquer paint completely fills crevices and dries with a luster”.