And of course post-chinagraph came the Stradeler(sic?) felt tips to which BE able referred. Two flavours, water soluble, easy to wipe off with spit and glove and a hazard in rain, and the permanent which one could, with care Sniff ☺ and could be cleaned off using the highly volatile solvent in a red SO tin until the HSE police banned it.
Cheap aftershave removes it.