I ran out of Oxalic Acid to pre treat socorro, so I figure I would try using hydrochloric acid to pre treat it. I used 80 ml in 2000 ml of water and the results were undistinguishable from using oxalic acid, so if anybody is thinking of using Socorro for pt/pd, it seems all that it needs is an acidification step.
Please mark your calendar to report back again in twenty years, Jorge. We'd certainly not want to make any premature judgements.
Funny thing is that a century ago HCl was the norm for clearing Pt. I wouldn't worry about an HCl presoak considering the alkaline clearing that I'd bet Jorge uses. Jorge, I've never tried Socorro paper. What's the surface like after having a presoak? With the exception of Fabriano, I haven't liked any of the papers that needed acidification because it kind of raise the tooth a bit.
The surface is still very smooth after the presoak, I then straighten it out on a hot press and it comes out just like new. Considering that the presoak is only 1 minute, you dont have it in the solution long enough to swell the paper too much. Oh, another thing, I was having a lot of trouble clearing a few days back and just for kicks I added a couple of pellets of Sodium Hydroxide, it cleared right up. So this might work in those days the paper just refuses to clear.
I can't write about Socorro impossible to find here, but I made some trials with Van Gelder Simili Japon, which is said to be the same paper without watermarks : the paper is smooth after a presoaking in oxalic acid (when printed and dried, it's also the smoother paper I've ever used, pure vellum, almost like silk). I don't know if they are really the same papers, Simili Japon produces wonderful delicate and "golded" brown tones in pure pd.
They are the same paper. Socorro also produces the golden brown tones. Socorro is Bostick and Sullivan's name for this paper. At the request of several of us using SJ several years ago, B&S arranged to have a batch run w/o the watermarks. I believe they are still selling from that same batch... Kerik
