Using QTR for printing color separation negs for tri-color gum

[donbga]

Is anyone using QTR to print seperation negatives for tri-color gum?

If so how are you linearizing the separations?

Don

 

[R Shaffer]

I use the same curve for all three separations. I linearized my QTR curve using the traditional cyanotype formula at a 2A:1B dilution @ about 1/2 full exposure ( my typical blue layer ). And then adjusting my magenta pigment & exposure with test strips to get it close to linear, by inspection, with that curve. Yellow was just some trial and error tests with prints, as the step wedges were impossible to read.

I think it was Loris who suggested using the cyanotype curve for all the separations. I like that I only use a single curve and it's close enough.

 

[donbga]

I use the same curve for all three separations. I linearized my QTR curve using the traditional cyanotype formula at a 2A:1B dilution @ about 1/2 full exposure ( my typical blue layer ). And then adjusting my magenta pigment & exposure with test strips to get it close to linear, by inspection, with that curve. Yellow was just some trial and error tests with prints, as the step wedges were impossible to read.

I think it was Loris who suggested using the cyanotype curve for all the separations. I like that I only use a single curve and it's close enough.

I linearize all three colors. The adjustment curves are all different and color rendition comes out much more precise. My method is to abstract in the computer with Photoshop and then print colors as accurately as possible although I do physical development at times. I build my curves with PDN.

I'm also interested to learn how Keith Taylor uses ICC profiles to print tri-color gum.

Don

 

[R Shaffer]

I linearize all three colors. The adjustment curves are all different and color rendition comes out much more precise. My method is to abstract in the computer with Photoshop and then print colors as accurately as possible although I do physical development at times. I build my curves with PDN.

I'm also interested to learn how Keith Taylor uses ICC profiles to print tri-color gum.

Don

That sounds like a far more precise accounting, well beyond my simple endeavor.

So are you making the separations and then reassembling them again, with appropriate colors, to check for accuracy and fine tune?

As I recall the article, Keith Taylor really did go to some extremes to fine tune his process. He brought in a specialist to create those profiles for him.

So is your goal to use QTRs ability to create ICC profiles? That would be very cool indeed. I don't see why you could not create a curve for each layer in QTR. Cyan and magenta are easy enough, but yellow just seems to fade into the paper.

 

[donbga]

So are you making the separations and then reassembling them again, with appropriate colors, to check for accuracy and fine tune?

I use a special file, Adobe's Ole No Moire,

http://www.jiscdigitalmedia.ac.uk/stillimages/advice/colour-and-resolution-targets/#t2

If I can get this file printed very accurately with my adjustment curves then I know I'm pretty close.

As I recall the article, Keith Taylor really did go to some extremes to fine tune his process. He brought in a specialist to create those profiles for him.

I'm not sure how the ICC profiles were made and applied. I could print a set of standard xRite/Gretag targets (as tri-color gum prints) and have a friend derive an ICC profile, which I assume I would apply to the image before generating the CMY seps in PS.

So is your goal to use QTRs ability to create ICC profiles?

No I don't think so.

That would be very cool indeed. I don't see why you could not create a curve for each layer in QTR. Cyan and magenta are easy enough, but yellow just seems to fade into the paper.

I don't think a yellow curve is any harder than the others. Remember also I'm using a colorized negative for each separation color. All three maybe different as well as their curves.

Don

 

[Bob Carnie]

Don

what type of end colour print are you making?

Bob

 

[donbga]

Don

what type of end colour print are you making?

Bob

Tri-color gum.

Don

 

[Bob Carnie]

Is the reference chart a scan of the gum print?
If so pretty damm good , you have a very good pallette and your grey scales look good.

Tri-color gum.

Don

 

[donbga]

Is the reference chart a scan of the gum print?
If so pretty damm good , you have a very good pallette and your grey scales look good.

Hi Bob,

The image shown is the reference image from Adobe. I can get very close to this, though I've never been able to get a perfect match.

Don

 

[Bob Carnie]

Hi Don

A perfect match is not what I am looking for as well, I would really like to see some of your prints, even in jpeg.
Is it possible to contact me via email, bob@elevatordigital.ca
If you are getting good grey card balance and good blacks , I feel you are on to something.
Do you every make a black Mask for detail and contrast?

Hi Bob,

The image shown is the reference image from Adobe. I can get very close to this, though I've never been able to get a perfect match.

Don

 

[donbga]

Hi Don

A perfect match is not what I am looking for as well, I would really like to see some of your prints, even in jpeg.
Is it possible to contact me via email, bob@elevatordigital.ca
If you are getting good grey card balance and good blacks , I feel you are on to something.
Do you every make a black Mask for detail and contrast?

Bob,

Essentially I use the same method for making gum prints as Christina Anderson does. Here style of printing is much different than mine and I think her work is much more imaginative. I strive for ultra smooth coatings and I trim off the brush strokes while Chris maybe more prone to incoporate wabi sabi effects.

http://www.christinazanderson.com/

I'll send you a few scans tomorrow, today I'm recovering from an emergemcy root canal. Wish I had a website but I don't.

Don

No mask is generated for detail or contrast. I usually print from CMY separations instead of CMYK seperations.

 

[Bob Carnie]

Hi Don

Root canal eh, I think I am having a better day.

I look forward to your email and small scans, I have bookmarked christina Z . thanks for the reference.

regards
Bob

Bob,

Essentially I use the same method for making gum prints as Christina Anderson does. Here style of printing is much different than mine and I think her work is much more imaginative. I strive for ultra smooth coatings and I trim off the brush strokes while Chris maybe more prone to incoporate wabi sabi effects.

http://www.christinazanderson.com/

I'll send you a few scans tomorrow, today I'm recovering from an emergemcy root canal. Wish I had a website but I don't.

Don

No mask is generated for detail or contrast. I usually print from CMY separations instead of CMYK seperations.

 

[Loris Medici]

Robert,

Yes, I use the same curve (derived from trad. cyanotype 2A:1B) for all colors - because I'm lazy, principally. (Also, I like to do gum over cyanotype - not tricolor, and it's very convenient to use a single negative for that purpose...) I think, ideally it would better to calibrate for each color. The problem is that, you have to pin down everything if you want to go for absolute / perfect calibration; I mean paints / paint concentrations and such. I think that would be severing the most important aspect of gum printing; flexibility. I rather prefer to play with paints / paint concentrations and dichromate amounts / exposure time, tools that gum process provides me. That way I'm not bound to specific working procedures and materials / I'm free! Also, I'm lazy (did I said that?) and it's too painstaking to calibrate tricolor gum. OTOH I think that it should be done definitely, if you're after true to life / close to perfect color reproductions la Keith Taylor. (I think Keith Taylor - or someone else for him - has done a custom CMYK profile for his paints...)

As a last note; you can color scan the yellow layer and use the information in the blue channel to calibrate yellow. I check my yellow layer that way, since my most preferred yellow is pretty transparent and pale... (Benzimidazolone PY151, but I seriously think about switching to PY150...)

Regards,
Loris.

 

[R Shaffer]

Robert,

Yes, I use the same curve (derived from trad. cyanotype 2A:1B) for all colors - because I'm lazy, principally. (Also, I like to do gum over cyanotype - not tricolor, and it's very convenient to use a single negative for that purpose...) I think, ideally it would better to calibrate for each color. The problem is that, you have to pin down everything if you want to go for absolute / perfect calibration; I mean paints / paint concentrations and such. I think that would be severing the most important aspect of gum printing; flexibility. I rather prefer to play with paints / paint concentrations and dichromate amounts / exposure time, tools that gum process provides me. That way I'm not bound to specific working procedures and materials / I'm free! Also, I'm lazy (did I said that?) and it's too painstaking to calibrate tricolor gum. OTOH I think that it should be done definitely, if you're after true to life / close to perfect color reproductions la Keith Taylor. (I think Keith Taylor - or someone else for him - has done a custom CMYK profile for his paints...)

As a last note; you can color scan the yellow layer and use the information in the blue channel to calibrate yellow. I check my yellow layer that way, since my most preferred yellow is pretty transparent and pale... (Benzimidazolone PY151, but I seriously think about switching to PY150...)

Regards,
Loris.

Oh that fits my style precisely!!

I'll have to try checking the blue channel, because that was my problem trying to curve the yellow. After I scanned it, I had to drag the sliders so far to get a 100% black that I had very little faith that the lighter steps were in any way representative of their actual values.

So your method seemed perfectly suited to my needs and has worked just fine for my tri-color gums. It took a few trial runs to adjust pigments & exposures and usually a forth layer to balance a bit.

 

[Green Rhino]

Using QTR.....

I've been working on tri color gum for the last several months using PDN for the negs. I have found that the curves and the colors are different for each of the colors although the cyan and magenta are pretty close. I'm finding that even with PDN I have to hand tweak the curves to try to get a neutral linear grey scale. I feel that after several months of testing colors, dilutions, papers and all the other variables that I am very close to where i need to be. I DO want to reproduce a 3 color grey scale accurately so that i know what my print will look like. (more or less)
I think the reason to bother with doing an ICC profile of the process is mostly to use it as a soft proof when preparing the file for separations. There may be some benefit to actually converting to that profile before making separations but I have not tested that yet. I first feel like i need to nail the greyscale for that work to be useful.

 

[Loris Medici]

Rhino, a 4th layer with the opposite color of the cast (to balance) is also pretty handy.

I usually don't try to replicate what I see on screen with gum printing, I prefer a little bit serendipity instead... That's (perfect color balance and close to perfect color matching) a job for inkjet printing methinks.

Regards,
Loris.

 

[Green Rhino]

i totally get the serendipity part, but I'm like to control my serendipity.
I'm working with other peoples images so I have to have some idea of expectations. Even "perfect" gum printing will not feel like archival pigment though.
The 4th layer is a great idea, the only problem i have right now is that the color correction is not quite linear. Thanks for the suggestion.

 

[Loris Medici]

Then do non-linear brushwork joking...

Well, if you want to print for others in a well-controlled way then you have to a. select the correct paints that play well together (which also gives you the palette you're after), b. prepare stock solutions "balancing carefully the colors" (always having "tri-color" in mind; you're not after perfectly saturated and strong layers, remember...) and c. calibrate carefully for each color, separately. Not that I do that myself, but that's what I feel as the most correct (or goal oriented) way of doing it....

Hope this helps somehow.
Regards,
Loris.

P.S. After seeing Livick's and Taylor's works, I can definitely say that's an endeavor I would never pursue myself...

 

[dwross2]

I agree with the sentiment of liking a little control over my serendipity. I have way too much 'serendipity' inviting itself into my life without putting out a welcome mat . Over the last couple of years I've been clubbering together a 5-color system. It's pretty much foolproof and flexible, if you are inclined to walk down the obsessive-compulsive path (my favorite route).

http://www.thelightfarm.com/Map/Silvergum/SilvergumAdvanced/SilvergumLayerGuideList.htm as part of a general tutorial set of gum-over silver gelatin. (The silver gelatin part isn't necessary.) http://www.thelightfarm.com/Map/Silvergum/SilvergumPart1.htm

I'm not even hinting that accurate color reproduction should be the first goal of gum printing. In my opinion, gum is the most sublime of all photo processes, most often at its best when it departs from 'reality' into visual poetry. There are some works of extraordinary beauty lurking in the hybridphoto gallery. Whether any of them were happy accidents or the result of finely honed technique, I can only say 'wow', and thanks for the inspiration.
d

 

[R Shaffer]

I'm not even hinting that accurate color reproduction should be the first goal of gum printing. In my opinion, gum is the most sublime of all photo processes, most often at its best when it departs from 'reality' into visual poetry. There are some works of extraordinary beauty lurking in the hybridphoto gallery. Whether any of them were happy accidents or the result of finely honed technique, I can only say 'wow', and thanks for the inspiration.
d

Can't agree more.

I don't think I would want to ( or be able to ) print gum for others aiming for a predetermined result.

It seems too free form and I feel I have follow where it takes me. Now if the client were willing to allow for such divergence of their vision, then it would be quite fun.

 

[Bob Carnie]

Don they look very good and encourages me to move forward, I hope to be able to see them this year when I visit with Sandy.
I would also like to send you some separated film for your opinion about my film output from the lambda.

Bob,

Essentially I use the same method for making gum prints as Christina Anderson does. Here style of printing is much different than mine and I think her work is much more imaginative. I strive for ultra smooth coatings and I trim off the brush strokes while Chris maybe more prone to incoporate wabi sabi effects.

http://www.christinazanderson.com/

I'll send you a few scans tomorrow, today I'm recovering from an emergemcy root canal. Wish I had a website but I don't.

Don

No mask is generated for detail or contrast. I usually print from CMY separations instead of CMYK seperations.

 

[Green Rhino]

QTR...

Bob,
What material are you using in the lamba, i had very little success with Fujiclear for making negs.

Anthony

 

[donbga]

Don they look very good and encourages me to move forward, I hope to be able to see them this year when I visit with Sandy.
I would also like to send you some separated film for your opinion about my film output from the lambda.

Bob,

Let me send you a copy of the Ole Moire File. If one can print this one accurately then one can do most anything they want to do. I'm definitely interested in the Lambda negs, I owe Burkholder a print, his Katrina HDR work would be a challenge. I'll e-mail you later.

Don

 

[donbga]

I've been working on tri color gum for the last several months using PDN for the negs. I have found that the curves and the colors are different for each of the colors although the cyan and magenta are pretty close. I'm finding that even with PDN I have to hand tweak the curves to try to get a neutral linear grey scale. I feel that after several months of testing colors, dilutions, papers and all the other variables that I am very close to where i need to be. I DO want to reproduce a 3 color grey scale accurately so that i know what my print will look like. (more or less)
I think the reason to bother with doing an ICC profile of the process is mostly to use it as a soft proof when preparing the file for separations. There may be some benefit to actually converting to that profile before making separations but I have not tested that yet. I first feel like i need to nail the greyscale for that work to be useful.

Just curious to inquire if you have met your goals yet?

Don

 

[Bob Carnie]

Anthony

I am currently using Rollie ISO 25 ortho, which works wonderfully.
I am going to buy Ilford Ortho 25 in the next ULF run, just waiting for pricing.

Bob

Bob,
What material are you using in the lamba, i had very little success with Fujiclear for making negs.

Anthony