I spent about half the day in the studio yesterday on this; not very exciting, but a handy tool for deciding how long to etch my plates in future. (It measures approx. 10″ x 1″… details after the jump)
Once the plate was coated with hard ground wax, I made lines with both my diamond point tool and my cork-handled scribe (in case there was a noticeable difference- not much). The lines were all the same weight at the start– so this shows the vast difference in weight and tone, depending on how long a line etching is left in the acid. This strip ranges from 5 minutes to two hours and five minutes in a 50/50 bath nine days old* in a shared studio. That basically means if the solution were brand new you’d cut the time down a bit, and if it were older, murkier acid you’d have to increase the time. I also agitated the bath for most of these, which accelerates the etching process slightly. Geekery and alchemy.
(Unfortunately, I forgot to clean the ink from the plate. I wiped it this morning but some of it has dried in there, so if I do any more prints it won’t be quite accurate.)
*Isn’t that from a nursery rhyme? Ferric Chloride in the bath nine days old!