U of S | Mailing List Archive | alt-photo-process-l | Re: oil printing

Re: oil printing

On Thu, 25 Sep 2008, Dirk-Jan Treffers wrote:


Just a wondering thought: Is it on purpose that you omit the use of hardener
in your gelatine layer? I also found more or less the same recipe on
alternativephotogrphy.com, and there also the use of a hardening agent like
glyoxal wasn't mentioned.
Is that correct, and if so, what's the reason for that?
I haven't seen what's actually on the website, but in the actual Issue #1 of Post-Factory (with subsequent mentions and further testing in later issues) the sizing section (in what you might call a "sidebar") MOST DEFINITELY has the hardening. I do NOT however put the hardener in the gelatin, for various reasons including in case I have some gelatine left (I vat size, so have mixed up a heap), I can use it the next day, or put it in the fridge, and keep for a week... also I just don't like the idea -- maybe because that's not the way I was taught, or there really is some difference, but IMO the hardener IN the gelatin is a PITA, with no advantage.

In fact I doubt just rinsing would avoid the glyoxal yellowing, if it's in the gelatin, tho that's just a guess, or maybe a prejudice, but reducing the glyoxal enough so it wouldn't yellow without being able to rinse it as a separate coat, might possibly have a downside. (Or, in other words, if it ain't broke, why fix it?)

And another question (you see, I'm curious)... why is that in oilprinting, a
negative is used, while in the gumoil process (which sounds more or less the
same...) you need a positive....
I forget exactly what "gumoil" was -- but remember that at the time I considered it absolute nonsense.... What the guy (whose name I also forget) was an absolute GENIUS at, however, was PR: I don't think there was a photo publication or a photo-related publication that didn't give him an article....

(And that was when we had a BUNCH of photo publications !)