Alternative color processes.

[Photo Engineer]

I might note here that the purity of many of the printing inks and hte halftone process itself are partly the cause of the need for the 'k' in the c/m/y/k printing system.

In photography, the continuous image, coupled with the less pure dyes add the 'k' component all on their own. Of course, there is always a tiny bit of retained silver in the dye image of chromogenically developed prints that contribute to this as well, making blacks black.

I have to agree with z-man in his posts. Don't reinvent the wheel and come up with a square one.

PE

 

[z-man]

COMO SE DICE "GLUE" EN ESPANYOL?

What are they?
juan

QUE TAL HERMANITO?

EN LA TIENDA ESTAN TODOS

try elmers for a start-i like "school glue"

vaya con dios a todo

 

[donbga]

"photography" and printing by press and or litho stone or photogravure or photosilkscreen are of course 2 sides of the same coin

my point is that a process camera operator could(and this one does) produce 3 color pigment prints , or mag +yelo over cyanotype or 6 color or what ever with complete consistency while asleep standing on his/her head

since the photomechanical processes and mediums continued to develope technically in the printing trades , the attempt by fine art types to duplicate past processes are re-inventing the wheel since what was everyday in the store supplies 100 yrs ago are of course no longer there

those emulsions and chemestries and techniques survive today in the printing industry with the modern equivilents of the old ingrediants

if i know how to separate a full color subject into a cyan, yelo, magenta and black printer(neg) and if i know how to finese each separate neg with a main, shadow and highlight exp and i know the properties of pigment inks and how they behave when suspended in sensistized emulsions---

how can a simple 3 color gum print be a big mystery?????

of course if you don't know the simple mechanics of pin registration of multiple negs and overlays and compositing in a vacuum frame with, say, 10 separate negs---

then i guess that eyeballing 3 negs into regestration and taping them down so as to get consistnt prints would be an overwhelming task that could only be accomplished by supernatural beings in mythical tales of old-right???????

a digital photographer who prints out via an inkjet is actually a "printer" since that inkjet is actually haltoning the images ,and, since they were captured via a digital camera were never actually continuous tone at all, so rightly they are not photography

but any continous tone "photographic" print must be converted to some type of "printing process" to be published unless you are only going on the web

if a "photographer" would learn just the basics of any printing process, then any of the "alt processes" become transparent in technique

Who makes negatives anymore? Isn't everything pretty much direct to plate now?

 

[sanking]

But looking at Hans and Chia's site, where they offer printing services in "four-color" gum, reminds me again what I told the original poster in a private message the other night: pretty much without exception those of us who work in color alternative processes make our color separations digitally, output to imagesetter or to inkjet printer (and I believe that includes all of the links that were provided here, except for the link to the French site where the person is making analog separations and hoping eventually to make gum prints from them but hasn't actually done that yet). I can only think of a couple of people I know of who have done three-color gum from incamera separations using filters, and as far as I know, they did it only once or twice out of curiousity; the bulk of their work is done with digital separations.
Katharine

Back in the days when there was no digital I made quite a number of three-color gum and carbon/carbro prints from in-camera separations using filters, or in some cases from separations made from transparencies with an enlarger using filters. My colleague Sam Wang also did a lot of work in color gum with in-camera separations. It was very complicated work and controls were quite limited.

Now that we have the computer and Photoshop to generate color separations I don't believe anybody in his right mind who is really interested in the final print, as opposed to ideology, would even consider wet processing color separations outside of doing so as a historical curiosity.

Sandy King

 

[Katharine Thayer]

[Moderator's Note: Unfair implication directed personally at another participant.]

PE is right; the need for a k layer in the cmyk printing process was generated largely by the impurities in the process inks used, and I'll take his word for the halftone process having something to do with it to. Whether one can achieve a solid black in gum with three colors and three layers depends on the pigments chosen and the concentration of those pigments. But if "not re-inventing the wheel" means using process printing inks and commercial printing methods to print gum, I'm not really interested in that at all.

Katharine

 

[Photo Engineer]

Katharine;

The 'k' layer is needed in the CMYK process due to the purity of some of the dyes which don't add up to give a true black but rather a gray. Also, the halftones used only add up to a gray. Impure inks with halftone also only add up to a gray, so it is a mixed bag of problems. Both of our statements are right depending on the mix and the 'k' must be adjusted for the type of ink used (or pigment).

Silver halide based color prints use impure dyes and no halftone, and therefore a 'solid' appearing image is obtained with no 'k'.

BTW, the new Kodak digital sensors essentially introduce a 'k' sensor into the imaging process to increase the speed and decrease the aliasing of the sensor.

PE

 

[Photo Engineer]

Thinking back on the carbro and other color processes, I don't remember them using a 'k' layer due to the lack of the halftone screen.

PE

 

[sanking]

Thinking back on the carbro and other color processes, I don't remember them using a 'k' layer due to the lack of the halftone screen.

PE

When people printed with continuos tone film separations there was no "K" layer used in either carbon or carbro.

Most of the master color carbon and carbro printers today are using imagesetter or inkjet separatioin negaetives and they use a "K" layer.

Sandy King

 

[Photo Engineer]

Sandy;

Most high quality digital printers use "k" images as well. They need this to obtain the proper tone scale with good blacks. I guess this is due to the dot matrix that the prints are ultimately made up of (the covering power of the inks?). I'm not sure. It certainly is not needed in conventional silver halide systems.

And the dyes from chromogenic development are not that impure either, just less pure than some azo dyes used in digital prints, and other printing inks, as well as Ilfochrome.

A magazine color print, produced without a 'k' image is a very poor quality image too. Surprisingly so, all things considered. The black ink image adds a robust character to the tone scale.

Dye transfer never needed a 'k' image either, but could compete on a par with the best press images I have ever seen.

Interestingly enough, Flexichrome images did need a black dye wash to enhance the image and give it a good tone scale. And yet, Flexichrome was a direct kissing cousin to Dye Transfer.

PE

 

[Katharine Thayer]

I don't have time to answer in depth right now, so for the moment I'll just point to my page that addresses the present question, whether a tricolor process, specifically tricolor gum, can produce black, and where the myth comes from that says it can't, and perhaps come back to say more about it later.

http://www.pacifier.com/~kthayer/html/Tricolorblack.html

 

[Photo Engineer]

Katharine;

It depends on the purity of the dye and the method by which it is deposited.

A very very pure dye set with sharp narrow band dyes has difficulty reproducing a black due to the 'holes' between the dye peaks. They reproduce brilliant saturated colors though. The study of sets of unit neutrals produced by narrow and broad cutting dyes will show you this, especially if you produce color patches along with the neutrals. You need lots more of all 3 dyes for the eye to interpret the mixture as black. This gives good saturation.

A dye set deposited as a set of dots, no matter what the nature, has difficulty reproducing a black due to the desaturation introduced by the 'holes' between the dots.

An impure dye set with contaminations, can produce a black but will give muddy colors regardless of the method of image production.

Density is density, and on paper support, you need at least about 1.8 - 2.2 for a good black. The holes in half tone are interpreted as desaturating the image by adding white.

PE

 

[z-man]

direct to plate etc

Who makes negatives anymore? Isn't everything pretty much direct to plate now?

depends on who what and where-here in nyc you can find the whole gamut-there's a letterpress operation not far from me

 

[z-man]

I WOULD GUESS THAT KATHERINE THAYER CAN'T READ

I would guess z-man has never made a three-color gum or carbon print.

PE is right; the need for a k layer in the cmyk printing process was generated largely by the impurities in the process inks used, and I'll take his word for the halftone process having something to do with it to. Whether one can achieve a solid black in gum with three colors and three layers depends on the pigments chosen and the concentration of those pigments. But if "not re-inventing the wheel" means using process printing inks and commercial printing methods to print gum, I'm not really interested in that at all.

Katharine

i can read

i have read your site

pretty images-quaint to my taste

i'm sure that you worked very hard to create them

the jerrys' catalog i just got in the mail lists quite a few watercolor and acrylic pigments in c/y/m/k-so how come you are still using old style approximations to process colors?

if lightfastness is the issue, i use my epson-the ultrachrome pigment inks on epson paper are good for many years-even in sunlight-my clients who have these concerns love them

i was producing art composed of 10 to 20 layers of individualy custom pigmented to order and/or pantone matched emulsion layers as work for hire in the adv biz 20 yrs ago

3/c was my process of choice for my fine art work 35 yrs ago

i've grown up since then

the fact that you are threatened by my comments proves most of my points

the fact that you are basically ignorant of the science or the art any of the common printing meathods is obvious from your mudled polemics

vaya con dios

 

[Photo Engineer]

z-man has a lot of good information here for us all. Listen to him.

I would be using the Epson pigment inks, but I don't like the surface of the image. I love full gloss, matte etc..... But he is right.

PE

 

[z-man]

YOU ARE A PRICLESS SOURCE OF REAL INFO

z-man has a lot of good information here for us all. Listen to him.

I would be using the Epson pigment inks, but I don't like the surface of the image. I love full gloss, matte etc..... But he is right.

PE

pe-thanx so much for sharing your knowledge and experience

your posts have been enlightening-so of course now i am going to bug you death with my questions

what about aging issues re pigment/dye combinations in gum/gelatine?

azo dyes-possible good choice for gum process? relation between azo and anilyne?

so kodak has improved chips with a black component-how?

foveon chip giving them compitition?

amonia necessary in casien emulsion-does that rule out azo for cheese prints?

i like to over print tea stained cyanotype with a layer colored by beet juice and then maybe another layer colored by tumeric for a rather surreal 4/c-too ransparent for most tastes-what about 'green' pigments for accurate 4/c?

lampblack is the obvious choice( katherine i do share some of your choices)for a black printer in a 'green' pigment palete-do you have any osha knowledge that would have bearing here?

vaya con dios

 

[Jerevan]

I think some of you need to re-read the OP. This thread has totally gone off the tracks now, into some weirdo showoff space for "experts" and BS talk.

Have a look at http://www.alternativephotography.com/ at, for example, the temperaprints or gumoils. It all depends on what kind of results you want...

 

[z-man]

YOUR WEBSITE AS A SOURCE OF MYTH

I don't have time to answer in depth right now, so for the moment I'll just point to my page that addresses the present question, whether a tricolor process, specifically tricolor gum, can produce black, and where the myth comes from that says it can't, and perhaps come back to say more about it later.

http://www.pacifier.com/~kthayer/html/Tricolorblack.html

you use a photofloodbulb to expose?!?!?!?!?

this is bulb that was in use to color match film 50 yrs ago-it primarily is a source of heat and by accident puts out a very low % of uv -it was recomended by technically challanged photo amatuers to those less knowledgeable

i tried it in the 60's and went to black light incadesent and then to flourescent

pro fine art silk screen shops used 8 foot cool whites in banks at the time so when i worked in those shops producing 4x6 foot serigraphs i learned that while slower than uv only bulbs it was a cheap to buy, build and use

right now you can buy high watt cfl uv screw base self ballasted bulbs that you can screw into any common household fixture and get real printing times of 10-15 mins wiht no heat and very little current draw-AND YOU WON'T BURN YOUR HOUSE DOWN

COLOR THEORY:

subtractive=c/y/m/k
additive=r/g/b

you are confusing and mixing these 2 the same way that a painter who mixes blu and yelo to get green is confused when he learns that yelo is pruduced on the tv screen by equal parts of red and green(light) and that green is a primary

please go to school and learn the difference between reflected and transmitted light

please learn the language of chroma and hue in context not in confusion

if you could do that then you could share your hard won experience with the rest of us in a language that has been codified for many years

we would all profit by this-most of all you would be in real control of your chosen mode of expresion

work smarter not harder

if you are not part of the solution you are part of the problem-that does not mean that you jump into the pot of gum but that you should stop creating the myths that you claim you are disproving

vaya con dios

 

[z-man]

GOOD LINK

I think some of you need to re-read the OP. This thread has totally gone off the tracks now, into some weirdo showoff space for "experts" and BS talk.

Have a look at http://www.alternativephotography.com/ at, for example, the temperaprints or gumoils. It all depends on what kind of results you want...

i basicaly agree with you

money talks and bs walks is how biz is conducted in the big city

[Moderator's note: personal attack deleted. Information=good. Aggressive posturing=unnecessary]

i started out with an offer to share real experience of 40+years

when i was billing $125/hr in 1980 i would never tell how i did things-i would have cut my own throat

photo engineer is not full of bs and i am not full of bs but some other folks are and i suppose that they make small money that way

THE GOOD THING IS THAT PE SHARED HIS VAST FUND OF PERTINANT KNOWLEDGE

NO GOOD DEED GOES UNPUNISHED

VAYA CON DIOS

 

[Jerevan]

Okay, sorry about the harsh wording. I became a bit grumpy about a general question devolving into minute details. Mea culpa.

Do share your knowledge. In the end it will benefit us all.

 

[Photo Engineer]

Jerevan;

I think that the sense of any thread is to follow the trend of the posts and try to answer the questions that evolve out of each answer as fully and as truthfully as we can.

If I don't do this, then I feel that I'm not living up to my responsibility of sharing my knowledge and continuing a legacy of photography in general.

I spent 15 years at Kodak as a color negative-positive systems engineer working on color papers and negative films and their processes. After that, I spent 15 years working on emulsions. In between, I worked on a lot of other stuff, because Kodak liked to make people learn a lot of subjects.

I try to pass that on here as fully and as honestly as I can, even though it might deviate from the OP, but re-reading the OP, I think we have not deviated that far considering all responses are in answer to some post posing additional questions or adding more information. I think, in fact, that we have done remarkably well, all things considered.

At least, that is my take on things.

PE

 

[Jerevan]

I agree fully with you, PE. And I know from your earlier posts that you have contributed a lot to our common knowledge base here on APUG.

It's always the challenge, as with any dialogue in any form: how much can you deviate from the original topic without losing the thread, if you pardon the pun? But I also understand the urge to answer every question as fully as one is able to. I know from my own experience.

Z-man: "let there be light"... yes, amen to that.

 

[z-man]

digital generation of negs for alt process-or in camera seps

Back in the days when there was no digital I made quite a number of three-color gum and carbon/carbro prints from in-camera separations using filters, or in some cases from separations made from transparencies with an enlarger using filters. My colleague Sam Wang also did a lot of work in color gum with in-camera separations. It was very complicated work and controls were quite limited.

Now that we have the computer and Photoshop to generate color separations I don't believe anybody in his right mind who is really interested in the final print, as opposed to ideology, would even consider wet processing color separations outside of doing so as a historical curiosity.

Sandy King

sandy

i thought this was the analog photo forum

pushing buttons in photoshop is easy and mindless

if you don't know how to create analog separations i suggest that you learn

my epson pigment printer can produce outstanding negs-but i call prints in any process made from them "hybred process" and i make sure clients know that they are not tru analog

when people are paying hard earned money they have a right to know what they are buying

an artist who can control all steps of the process can master it

a hand made knife or jewelry is very different from those labeled "bench made" which tells the buyer that production machinery was used to make it

i suggest that a platinum print that is made from a digital neg because the final print is 20x24 and the original neg is 35mm should be called "bench made"

if the original neg is 20x24 then i suggest it is "hand made"

if you can make separations in camera then your 3/c gum contacted from them is certainly analog and hand made

if you are doing all your seps in photoshop and the original was a 35mm neg and your final print is 16x20 YOU MUST CALL YOUR PRINTS "HYBRED MACHINE MADE"

you have relinqueshed your control of your art to a machine

not a problem if you make sure that your clients are aware of the difference

vaya con dios

 

[sanking]

Z-Man,

You sound like one of the old-testament prophets come down from the arid mountains to spread God's word ? Do you print on stone tablets?

Sandy

 

[RoBBo]

Z-Man,

You sound like one of the old-testament prophets come down from the arid mountains to spread God's word ? Do you print on stone tablets?

Sandy

Gotta say, I'm starting to like Z-Man, if he wanted to print on stone tablets, I'd help him cut them from the quarry.

 

[Photo Engineer]

Having made separation negatives both ways, I see the merit of both and the problems inherent in both.

I feel that either digital or analog can be used as long as everyone knows exactly what they are seeing when they get the finished product. I also have to admit to getting frustrated, tired and hot in both the darkroom and in front of the computer.

PE