U of S | Mailing List Archive | alt-photo-process-l | Re: tips for using dry pigment

Re: tips for using dry pigment



On Tue, 12 May 2009, phritz phantom wrote:

hello judy.
i got the P-F issues on friday (that was rather quick). thanks! i've been reading like mad since then.
Actually, phritz, you got me reading like mad too... because I once tried an old formula for gum printing that also called for sugar, and my tests showed it did nothing to improve the coat, in fact rather spoiled it. So seeing this mention of sugar I was skeptical...

However, if there's any alt process I know less about than making carbon tissue, I don't think of it offhand. So when it was revealed that your "glop" was for carbon tissue, I could only try "the literature." It was already late at night, however, and after I checked the few contemporary manuals that came to hand, none of which had anything relevant about carbon tissue (the older literature assumes you're buying the tissue from the folks still making it), I schlepped downstairs & REALLY wore myself out carrying Christoper James's 2nd edition back up again. (The only improvement I could suggest for that book, besides some hyphen control -- he tends to put them in odd places, which I'm a crab about-- would be to publish it as a set of two books, so we could lift one at a time. Otherwise it never ceases to amaze me. In fact it's the only manual I've not yet found an error in, and even the great classic "Keepers of Light" has some silly nonsense, cut and pasted down the line by folks who should have known better... But I digress...)

As I was saying, worn out by carrying the James book upstairs, I let it fall open to the first chapter, which I'd never read (as I generally head right for the point at issue)... and admit being charmed -- a lot of history & beguiling illustrations (especially "Portrait of a Blind Man Holding a Cat," ca 1850) but, I digress again...

On page 405, James tells us that "According to W. Jerome Harrison's 'The Chemistry of Photography' (1892)," Sir Joseph Wilson Swan "patented a practical and easily accessible solution to the confounding and vexing problems of carbon printing." Among these was "mixing a little sugar into the gelatin to make it less brittle when dried." Many other improvements followed, with carbon's greatest popularity from 1870 to 1910.

sugar: i need the
sugar to keep the curl out of the carbon tissue. i can't go
below 60gr/liter. i've tried 40 and it was too little. one time i completely forgot the sugar and the result was a tissue that was almost unusable because of the curl.
However, James adds, "Of late there is a renewed interest in these processes, in no small part [due] to Dick Sullivan's new and easy to use, carbon tissue." There follow details on sensitizing & exposing the tissue, "mating the tissue to the support," and developing the print. The next section is "Making Your Own Carbon Tissue" in case "you decide not to purchase the prepared and perfect tissue from Bostick & Sullivan." Again, detailed instructions, including that "It is nearly impossible to make tissue without also making a mess."

The formula includes 90 g 250-bloom hard gelatin, 30 g table sugar, 10 g glycerine, & 12 g paint-store lampblack pigment. Benjamin Moore stores, James says, "usually sell pigment in 1 quart cans...far more economical than art store pigments."

He also says, "Sullivan has written a new manual to go with his new tisssue and I have relied on his expertise to a great extent in the production of this chapter... For more information, go to www.carbonprinting.com."

I've probably copied more out of the copyrighted text than is legal, but there's nothing about mortar & pestle. Instead you let the gelatin swell in cold water, let it sit 20 to 30 minutes, fill beaker with water to 1 liter, place in crock-pot with more water, & set on high... The gelatin will melt in 30-40 minutes, add sugar & stir til dissolved. Add the glycerin, add the pigment & STIR, MIXING WELL. "YOU DO NOT WANT ANY PIGMENT SITTING ON THE BOTTOM AS IT WILL CLUMP & GET GRAINY IF IT COOKS THERE." NOW YOU LET THE BUBBLES ESCAPE, KEEPING HOT FOR 1 & 1/2 HOURS AT LEAST... THEN POUR & SPREAD WITH COMB." (Please excuse capital letters, I must have hit the caps lock in error.)

But just reading this wears me out... Have you considered a nice simple, easy process like, for instance gum printing ???!!!

best,

Judy

i've read carbon formulas that called for a lot of strange stuff, honey one among them. i got the forumla with sugar from the sandy king article on unblinkingeye. i think the sugar is not supposed to do anything image-wise, but only keep the tissue flat.

whoops. i used the wrong word, "brick and mortar" for "pestle and mortar". of course i was not grinding it with a brick. i do use "grinding" to mix the pigment with the fluid, not to grind the pigment finer. i read a little about how it's done in painting and they all used a thing like a mortar and pestle to mix it.
i don't have problems mixing for gum, it's fine after just a little mixing with the brush. carbon is different, it's a lot more pigment (7gr for 500ml pigmented gelatin solution). when i put the water into the mortar, the pigment floats on top at first, then goes into the solution while mixing. i thought about adding a dash of alcohol to get rid of the surface tension of the water. it would make the process easier and less messy at the beginning.

i have to pre-mix the pigment in a little bit of fluid before adding it to the whole batch; mixing it in the 500ml of gelatin would be very messy and impractical. so i just mix it in a little bit of water, then add it to the whole.

i still haven't got a stouffer-step wedge, but i just prepared some carbon tissue to do the same testing with chart throb (digital step wedge and analysis program), i just did with gum printing. so, soon i'll be able to say more about that.
(i could post the scans of my comparsion of 5% vr saturated ammonium dichromate, if interesting to someone and not a complete bore fest. saturated is highly superior, step-wise. but i might try and use 5% for my shadow exposures)

phritz