Gum Color Control

[dwross2]

Here's a thread started on APUG. I'm posting my response here.

(there was a url link here which no longer exists) and the OP:
"Hello all. I've realised why some of my gum dichromate prints are not loking too good; it's because they are not contrasty enough. Does anyone have any tips for colour curves in GIMP or indeed a curve file ? Or would it be good enough just to alter the contrast to a level that loooks OK ? " Stephen

I never had much luck with 'curves' as a color tweaker, so I developed a system that's almost fool-proof (I would know! ) I usually print over silver gelatin, but the color layers are the same as over plain paper. I advocate for a black K-layer as a way to add density and depth, but I know many gum printers who manage without it. I wish Katherine Thayer were still with us to weigh in with her sage and experienced advice. I miss her. But, for what it's worth, here's my system:

TheLightFarm - Gum color layers worksheets

and the section of my website that talks more about the details of both 3-color and 5-color gum printing, including how to use the worksheets:

TheLightFarm - Silvergum Printing

 

[R Shaffer]

Here's a thread started on APUG. I'm posting my response here.

(there was a url link here which no longer exists) and the OP:
"Hello all. I've realised why some of my gum dichromate prints are not loking too good; it's because they are not contrasty enough. Does anyone have any tips for colour curves in GIMP or indeed a curve file ? Or would it be good enough just to alter the contrast to a level that loooks OK ? " Stephen

I never had much luck with 'curves' as a color tweaker, so I developed a system that's almost fool-proof (I would know! ) I usually print over silver gelatin, but the color layers are the same as over plain paper. I advocate for a black K-layer as a way to add density and depth, but I know many gum printers who manage without it. I wish Katherine Thayer were still with us to weigh in with her sage and experienced advice. I miss her. But, for what it's worth, here's my system:

TheLightFarm - Gum color layers worksheets

and the section of my website that talks more about the details of both 3-color and 5-color gum printing, including how to use the worksheets:

TheLightFarm - Silvergum Printing

Your truly a mad scientist. I'll need to spend some more time reading your method of making color separations.

 

[R Shaffer]

As to the original OP. It is very easy to get muddy prints if your negatives do not have sufficient contrast and a simple tweek with a curve would help.

Also, I usually have as a final layer on tri-color ( 4th layer for tri-color ) or multi-layer prints either black or blue to sink the shadows. I like a good 'bottom end' to get my prints to pop.

 

[stephen_gray98]

Thanks for the info guys - I'll take a look !

SPG

 

[donbga]

Here's a thread started on APUG. I'm posting my response here.

(there was a url link here which no longer exists) and the OP:

I highly recommend using Mark Nelson's Precision Digital Negative system for building curves for tri-color or 4 color gum printing. I don't wish to sound redundant but Mark's system is precise. Each color pigment will have it's own curve shape, sort of a signature if you will.

 

[Green Rhino]

i concur with Don on this. PDN is a great way to get each of the layers to work well. Each color has it's own curve, color and time that is optimum for it. I do am in the process of tweaking the curves that PDN generated to make it strickly neutral but the curves made have gone a long way to getting me close

 

[dwross2]

It's great to see so many recommendations in one spot. I'm quite sure there are at least a dozen very good systems -- probably all equally able to create perfect color layers. In my opinion, the point isn't that one technique is better than another at generating technical perfection, but rather that working strategies are not a 'one size fits all' situation. If a new gum printer isn't getting what he or she wants, it's not that they are insufficient to the task or that gum is too hard. It is almost certainly that the technique they are using isn't one that fits either their brain or their work style.

I've got a few kinks in my brain, and admittedly I'm a bit of a mad scientist. I think that places me with the majority of artists. There are a lot of systems that try to cram us into a faux imperical mold that promises easy precision. My opinion: I don't think it's the right Way for everyone.

 

[PVia]

After years of reading article upon article about gum negatives and getting nowhere by trying everything under the sun, I now print gum (mono and tricolor) with my pt/pd negs. Awesome contrast, quality, etc...it pays to experiment and tinker, go against the grain, be contrary...

 

[stephen_gray98]

Sorry to be dumb but what is/are pt/pd negs ?

SPG

 

[dwross2]

The negatives used to make Platinum/Pladium prints. Pt and Pd are the abbreviations on the periodic table of elements. Both Pt/Pd prints are often just called platinum prints, although most prints going by that label are a combination of both elements. I understand combining the elements makes for a better print than pure platinum, with a slight reduction in materials cost. A platinum printer will be better able to elaborate.

PVia, do you use the same negative for all three color layers?

 

[PVia]

Denise,

For tricolor negs, I'll use the same profile/curve as my pt/pd negs, and then make my separations.

 

[Kerik]

My gum printing is almost always combined with a pt/pd print and I use the same negative for both. I've been doing it this way long before I was using digital negatives. I completely concur with Paul. One caveat is that I don't do 3-color gum - it's just not my thing.

 

[dwross2]

Denise,

For tricolor negs, I'll use the same profile/curve as my pt/pd negs, and then make my separations.

Your gum prints are very lovely. I particularly admire the depth you achieved in 'Fig'. Excellent.

I might be missing something, though. You aren't making 'tricolor' prints in the traditional sense of separation layers (??). It looks like you are using the same negative with different pigments to build up a custom monochrome that has the nuance of layered tones, or making triptychs of different monochromes. Whatever you're doing, it really works.

 

[PVia]

Thanks, Denise...

I do both...the fig is one neg, 5 layers (?), different colors each layer, sometimes a double layer of one color, changing dichromate ratios and/or exposure times to get the color to go where I want it to (actually anyone doing gum realizes that last statement marks me as delusional, but I digress...)

When I do true tricolor, with 3 different negs/separations it looks like this...from my photostream on Flickr:
Gum prints - a set on Flickr

I basically use Keith Taylor's published method, and have hacked it here and there to make it work for me. Keith is my hero when it comes to tricolor...

 

[stephen_gray98]

Some great info so far ! If only I had more time though .... I read an article on Keith Taylor on Unblinking Eye; where can I get his published method ?

SPG

 

[R Shaffer]

that last statement marks me as delusional

Delusional.... I find sacrificing chickens and goats also works, but only when there is a full moon.

Those are great looking prints Paul and delusional is just a state of mind.

I first saw the Kieth Taylor article in View Camera, however it is pretty close to the one on unblinkingeye.

 

[PVia]

Yep, same thing as Unblinking Eye...there's also a little article that you can buy from Ag magazine on Lulu for 99 cents or something like that.

I like the UE article because there are more photos of the process...

I do not mount on aluminum (yet!) but I use Fab soft press for paper, and do not preshrink or size.

I should make a little video or something...oh, and thanks for the nice words, Denise and Rob...