Multiple Layer Gum Printing

I would hope this thread can be helpful for those wanting to make Unique prints. This thread will be focused on Multiple Gum Printing. I understand that there will be flack from those wanting the site to remain pure, I feel weird even having to say this but , when I refer to separation negatives though I generate them digitally there is a long history going back 60 -80 years of printers making separation negatives the old way.

Since I have fully embraced a mixed digital and analogue workflow please keep this in mind and I would love to see other Gum Printers add to this thread.. specifically before and after images with details on how one got from A to B.

I will start with one of my images that is in my Media Page.




So the original is a 8 x10 negative photographed in my simple studio with hot light and Century Camera.

I made an enlarged negative to 16 x20 of this image on film.
The Paper Hannamuhle Platinum Rag was then coated with a gum Mixture using brush work.
Daniel Smith Ochre 1 unit
Gum Arabic 1.3 units
Ammonium Dichromate 10 % solution 1 unit.

this mixture was shaken over 100 times by hand in a glass container then spread on the paper using Home depot brush with the corners rounded, followed by a final swipe with a very good sable brush slightly dampened to smooth the coating.

the Paper dried for 40 minutes and then the original negative and paper was punched together for registration and the print was put in the vacuum frame with pins and an exposure was made on the Nu Arc.

After the exposure the print goes into tray one (Distilled Water for about 5 min) then into tray two (Water from Tap) for another 5 min. There is some agitation but now much, the print is face down in the water.
Finally the print goes into tray 3 where I have a soft flow of water running and I use the water gently to take any loose pigment away and if required do slight brush work on the print . But for the first coating I usually like to keep the Ochre solid on the print.

the print is dried... then we coat the Print again with the same Ratio of Pigment , Gum and Dichromate but this time I use Thaylo Blue and Red mixture for the pigment.
Let the coating dry and with the exact same negative expose again with the same time.
Water wash out is the same, but this final time we use the water and slight brush stroke to take away some of the blue and reveal the ochre below which creates colour contrast , Density and overall balance.

 

are they traditional rgb type separations like i use for in camera negatives and tri chromes
or are they exposed or processed a special way to only highlight the highlights or mid tones &c ( does that make sense ? ) ?


In this particular image the negative is created from the main image, there is only one neg and its printed twice- Kerik does this a lot and I got the method from him Years ago at Photostock.

I will post a few images in awhile where two or more negatives are used, to boost shadow Dmax for Gum over Palladium, and as well creating special effects by taking the image and creating different negatives from the regions of the scene.
When you get into this you need to be very careful about registration needs.

 

Hi John

Seems right now we are the only two working this thread but thats ok .

So here is an example of how two negatives can work together. In the old days one would separate the film out into three negatives, cyan, magenta
and yellow.

Here the image actually looks like my Gum Print so there was little or no need to use the Cyan separation negative.

So make the Yellow negative to size 16 x20 and the Magenta negative to 16 x20. with registration marks in the rebate area
one can strip the two negatives together.
I use a stroseer system punch and pins to do this, the three pins are permanently on the stripping table which can be a big light box . and free pins are
then used within the vacuum system of the plate to go through the punched paper , film combination. Its actually quite easy to register and in most cases
you do not need the guides in the rebate as one can easily see the underlying image when putting the films to strip together.

I use Hannamuhle Platinum Rag and I do pre soak the paper to shrink it and for a two gum will now not mount to aluminum as I have found the registration holds
nicely at 16 x20 size, I am getting a larger plate burner to do full 22 x 30 sheets and I may find the need for water shrinkage and aluminum mounting- will see.

The Yellow coat is laid down first, as you have to be sure if the pigment you are using is transparent or not and I have found that the Yellows are usually
semi transparent or opaque , therefore its wise to lay Yellow down first. Expose normally and wash out normally as described in Post #1 , I do not stress
the layer this time as you will find the yellow image quite faint.

After the print is dry I use transparent Magenta Pigment and expose , washout as normal and the result is the two tone image.


Sam Wang in South Carolina was the pioneer in this type of duotone work, where he would mix a red or Cyan negative with a Yellow or Blue negative
and do gum over cyanotypes to create a very realistic rendering with minimal colours. I spent a lovely afternoon at Clemson picking his massive brain
about this and frankly his work inspired me to go the gum work and of course his student Christina Anderson had a lot to do with convincing me this was a great process.


Bob

 

Thanks Sly - I have seen a bunch of Ginettes Lumens , actually she came to my darkroom and taught a bunch of us how to do them..



This is an image going into my fall show at Propeller Gallery in Toronto, and I am printing to a common size for about 15 tri colours.

This particular image does look like the jpeg I am posting its originally a solarized colour negative.
For this we need to make three separation negatives which are the Cyan, Magenta and Yellow. there is not black or palladium base.
This paper is shrunk and mounted to aluminum- but this weekend I am going to be adventurus and try no mount and see if I can hold the registration.
I am making these prints 13 inches on the long side and I am punching the film on the long side to keep the registration as close as possible to the image.
The paper is Hannamuhle Platinum Rag and I am using Thaylo Blue (green shade) Quinacridone Magenta and Indian Yellow, all Daniel Smith Pigments.
my pigment to gum to amonium dichromate 10% is basically 1 pigment 1.3 Gum and 1 AD and I really shake the crap out of the mixture.
Home depot foam brush to apply with cut off rounded corners and a final brush (slightly dampened sable brush)
Let Dry for 30- 40 min in dark room, I use Nu Arc exposure unit 120 units and wash our with water at room temp.

As discussed before the first layer in this series is the Indian Yellow, then the Magenta followed up by the Cyan.

After the Yellow and Magenta layer the image looks pretty nice , but when you add the Cyan all the detail pops in and the whole image comes alive.
the three distinct washouts take about two days but I work on about 10 images at a time so a lot can get done in a short period of time.

Like Christina Anderson, I will use water at the very end to bring out highlights in each layer and create local contrast.

Bob

 

I think you could resource any dye transfer manual or you could make separation negatives with line screens . Using red green blue filters under
the enlarger would be the way I would attempt this as well.
Also you could purchase ortho 25 and make enlarged negatives , I would think you would need to do dupes first.

Since I am now using three lasers to expose ortho 25 I am not sure if I am walking into grey area . So for now or at least till Sean makes
the changes I will just discuss the negative making side casually and let one imagination fill in the gaps.

 

I like the cyan last in tri colour as it is the final addition to the work and in our visual world cyan is a dominant colour, the yellow and magenta kind of set the stage, adding the cyan fills the space and defines the image
But not always John as I am using many palettes for my work, if an image screams green cyan then I would do the Cyan and Yellow negatives with corresponding pigment.
Yellow and Cyan create green see chart below.



In this case I laid down the Cyan first as it is the dominant colour and I hit a second exposure with the Yellow and the two colours bled together to make the green areas.. This is important to know when doing gums that the colours do blend together and a strong understanding of the colour wheel will go a long way.



I have had this colour wheel or a similar one hanging in all my darkrooms since the day I started colour printing 1974, without it I feel I would be lost.
When purchasing your pigments you should try to keep this in mind, lightfastness 1 - and transparent.

I would be hesitant to discuss how to view a gum print by lifting the back of the contact frame as I do not think it relates as other processes but I could be wrong.

I have found 120 units of light work all the time for me so with some trial and error you should be able to calculate - unit of light and time it would take in the sun
It is not as strict as you would think and certainly not a time and temp exact process as Pt Pd or Silver

 

John - for gum work it does not have to be c m y , you can use r , g, b and of course a straight greyscale

There is a lot of variations, I just tried an all RGB neg workflow and a CMY neg workflow with the same paper.
the best reproduction by far was the CMY and I blame it on the pigments I chose to work the RGB.

 

I use amonium dichromate 10% solution in exact relationship to the pigments.

Re pigment I use Daniel Smith because Christina Anderson recommended them and they work well in my space.

15ml tube plus 45 ml gum arabic (pre made factory) - this becomes my stock solution for any pigment and I do not change this ratio for sanity sakes, Because
at this moment I have over 15 colours going and I want to keep my sanity.

I will mix this Pigment solution (three units) +Ammonium Dichromate (three units) + Gum Arabic ( 3.5 units) and this is standard for a 16 x 20 coat.

Larger or smaller prints I will adjust the final amount but the ratio is always the same.

Your print actually looks normal to me in density for a first coating.... I have also read and seen that black pigment is a tough pigment to work with.
I prefer burnt umber, raw ochre, or sepia as my first coat.

Then when I put the second coat on , I will use a complimentary colour to the first and this has the effect of deepening the print in tonal values and I use water to leave areas
white.

regarding white, I never strive for white white, not sure why but I am a fan of Sudek with a printing style of grey on grey on grey.

Regarding flacking I cannot help you but can say when I shook the mixture 100 times before coating and using distilled water in the first bath I got fantastic repeatable results.

As above simple foam brush ( not dampened ) to put the pigment on and then a really fine quality sable brush with the very edge slightly dampened to give one final brush
over to make the surface smooth.
the lines are caused by your brush being angled at the ends, I cut the corners round to avoid this streaking.

You should go to a graphics supply house somewhere within 200km of your place and try to find a good registration punch system so you can easily do multiple hits with the same negative.

Regarding Negatives... If it looks like a duck , walks like a duck , quacks like a duck , its probably a duck..

We should never be afraid of the negative stage as I have found any normal looking negative that would print on a grade 2 or 3 silver paper is good for my purposes in gum.
If I want to make a pt pd then I look for a negative that would print on a grade 1 for silver(mor contrasty neg)
so if it looks like a negative, you get the point.

Unlike Pt Pd and Silver - Gum is a wash off process that can be controlled by simple exposure and wash off methods including brush and soft water flow.

 

This image is by Bryan Helm who is located in New York- he has been fascinated with motorcycle culture for over 20 years and I have printed for him in alternative
methods.

This image is a tri tone gum using three negatives made from a digital capture.

Negative one is a full scale black and white conversion of the original scene- with this negative I lay down a sepia tone to create a monochrome sepia print which on its own
looks pretty vintage.
Negative two is a sky only negative which I then lay down a cyan with black mixture to create the top, since the bottom of the negative and part of the bike and rider do not record on the film
the gum pretty much washes away in the bottom and leaves blue sky and sepia rest.
Negative three is the earth only and for this I used a mixture of burnt umber and orange mixture and since the sky and top of the bike rider do not record all the pigment in the sky washes off and leaves the sky blue, the rider a mixture of three colours and the earth sepia and orange.

This body of work is coming out to Vancouver next spring in the Capture photo festival.

 

Hi John
Yes that is pretty much the idea where you make a negative from different regions in the original.. in this case I isolated the blue sky and the brown red earth as separate areas from
the main over all negative.

BTW in the magic box I reduced the blue content and the brown content in the main negative so these regions would print lighter than normal and then the blue and brown filled in more with the second and third printing.

many things could be added, for example you mention a texture screen, one could coat a fourth colour and hit a texture negative only to add a pattern.