Re: Miracle size for gum
Judy...
Gamblin PVA Size is what you
want...go to Utrecht...don't bother with anything
else.
I do have PVA adhesive here at
home and I use it for bookbinding. It's a glue...
Paul
----- Original Message -----
From: "Christina Z. Anderson" <zphoto@montana.net>
Sent: Sunday, October 11, 2009 6:40 PM
Subject: Re: Miracle size for
gum > ----- Original Message ----- > From: "Judy Seigel" <jseigel@panix.com> >> Sometimes I have trouble staying out of an argument, because who doesn't >> love a good argument? Research shows, moreover, that an argument about gum >> firms the skin and makes the hormones flow, while discouraging outsiders >> from attempts to muscle in on the process. But the gum argument (or >> "discussion") I'm staying out of now is because I don't know what the hell >> folks are talking about & decline to expose my ignorance. > > Judy, > I hear ya, I hear ya...I agree in that testing and arguing about gum doesn't > get gum printers or gum prints made. The proof in the validity of gum > testing comes in the work produced, IMHO. Now, that will open another can > of worms--what constitutes a "good" gum print and I daren't touch that with > a ten foot pole. But there are a lot of excellent gummists who never pick up > a step wedge. They just make prints. > > I find it extremely useful that when we discuss things as tonal range, > miracle size, more or less dichromate, more or less exposure, etc. we find a > way to talk apples to apples in gum, and that is where the lowly step wedge > comes into play for me--scientific or not, used and discussed correctly or > not (thanks, Etienne). > > Thus when a statement is made that such and such produces a longer tonal > range, I take it to mean that the maximum "black" for that color pigment has > been reached (obviously not black as in a glossy silver gelatin) as well as > paper white has been achieved, and those steps in between can be counted and > compared to get somewhat close to apples to apples. Either the step wedge > shows just a few steps, or lots of steps. And each step on the step wedge, > being film, is a difference of 1/3 stop or 1/2 stop that corresponds to > increasing or decreasing hardening of gum, whether that hardening equates or > not to a measurable log of density. > > When gum gets a bad rap as being a "two stop process" which, I assume, the > writer meant there were only 4 **steps** of color on the step wedge or 6 on > a 31 step (writer is well known, and certainly gum has a reputation of being > a short scale process), then it is important to discuss what kind of tonal > range people who gum print frequently are getting. I personally don't find > gum THAT short scale of a process. Certainly not as tonally long as > platinum but long enough. > > But as has been found in this discussion, as usual anything gum, the > parameters of the testing is different from gummist to gummist and therefore > no longer compares apples to apples anyway. And then we get into arguing > over how many angels dance on the head of a pin. > > And then it's interesting to see your advice come back to you--or not. > Seems to me a while back on this list I dared to suggest that past a certain > point more dichromate wasn't necessary--it didn't decrease exposure enough > to warrant the extra amount and I settle now on an easy to measure 15% am di > (used to use 7.5%, one list member only uses 2.5% and her exposures are not > lengthy). That by a step wedge. Wow did I get creamed in that discussion. > > Seems I also mentioned that using EQUAL strengths of ammonium, sodium, and > potassium dichromate had different speeds--ammonium being the fastest, and > for all the solubility that sodium has, it doesn't have much oomph--more > like potassium at the same strength (used 10% for all). That I found by a > step wedge. I know at least Sandy King corroborated and even gave a > percentage comparison between am and pot di. Oh, and Kosar as well...but > man, the first time I mentioned Kosar I was creamed. > > So even though using a step wedge on a process that really isn't > photographic in a sense (just photosensitive) and talking about it in > photographic terms, that step wedge sure is a handy little thing... > > OH, and having been cleaning out my dimroom all day, I finally found my > motherlode of step wedges. I had lost them I thought permanently, and > ordered 3 more 4x5s and 1 8x10, and NOW I have a passelode of the things, > heheheheh. I just love this cleaning thing. For some reason I had put them > under a towel on top of which I let gum prints dry before exposure. > > Back to size, Marek, I am going to run right out and buy that miracle size, > lemmetellya. If I could find a nontoxic size that also printed a LONG TONAL > RANGE (gasp) I will personally come down to TX and kiss your cheeks!! And > Jeremy Moore, that video thing is a great idea to do for the list! Good > discussion... > Chris > > __________________ > > Christina Z. Anderson > http://christinaZanderson.com/ > >
|