Summer of Alternative Photography

Van Dyke Brown Print

• Selenium toned

Gum Print

• Multicolored gum

Gum Oil Print

Carbon Print

Cyanotype Print

• Coffee toned
• Tea toned 
• Tannic Acid toned
• Cyanotype on glass

Lumen Print

Chemigram

Anthotype

Gum Printing - Operation

Anyone who played the Milton Bradley game "Operation" when they were younger knows the feeling. You take a deep breath, get you fingers just right on the tweezers, pick a piece that you want to try to take out, slowly, very slowly, you work the tweezers into the space. You are almost there. You squeeze the tweezers together and pick up the funny bone, then you start to raise it out of the body. BZZZZZ!!!

Damn!

Gum printing is similar. But much much worse.

This morning I had the following experience.

I spent time going through my photos to choose one I wanted to print.

I made converted it to a negative in Lightroom, carefully adjusting the shadows and highlights to print well (or not). I added a halftone screen in Photoshop to encourage smother tonal transitions.

I fed the Pictorico OHP transparency film into the printer and set the drying time per pass to 30 milliseconds.

Slowly, but surely, the negative emerged from the printer.

I registered the negative onto the watercolor paper by marking the corners of the image with an imperceptibly small dot.

Earlier, I had prepared the gum emulsion for coating the paper. 12ml of gum arabic was drawn up into a syringe and put into a small metal mixing bowl (which was prepared by mixing 30g of powdered gum arabic with 100ml of water and stirring, stirring, chilling, stirring, waiting, stirring, etc). 9g of lamp black was carefully weighed and then mixed into the gum. Mixing, mixing, mixing. Then, donning rubber gloves, another syringe draw 12ml of poison, I mean Potassium Dichromate from its light safe bottle and injected it into the gum. Mix, mix, mix.

The next step is tricky, and critical. The emulsion needs to be coated evenly and smoothly onto the water color filling the area that will be covered by the negative. I use two Hake brushes. One for the first coat. Big, fast, accurate strokes are required to get an even coat before the emulsion starts to gel. Brush strokes and brush hairs are the enemy. Much cursing happens at this point. So far, I am living with slight imperfections. Maybe a sponge brush would be better. The second brush is used at the point where the gel is coated and is starting to get sticky. The idea is to smooth out the surface as much as possible. Long even vertical strokes, long even horizontal strokes both with little more than the weight of the brush touching the surface. Did I mention that the paper starts to warp from the moisture making it necessary for the brush to traverse a hilly landscape. All the while wearing rubber gloves to keep from accidentally absorbing chromium into my body.

Then the paper is hung in a dark space to dry. A fan is helpful.

The exposure then takes place in a UV lightsource box. The paper is carefully sandwiched with the negative between two pieces of heavy glass (I don't have a contact printing frame yet). The negative must be in tight contact with the paper. UV light (wavelength 370 nanometers) is dangerous to the eyes, so UV protective sunglasses are worn. After many tests and trials (hours and hours), I have settled on 1 minute exposures. Even this is not certain.

The print is then removed from the lightbox and placed face down in a water bath. It is now that things get tricky. The gum that is supporting the pigment gets soft. It has been slightly hardened where the UV light made it through the negative (shadows) but it is still very very fragile. Any slight touch on the bottom of the tray, back of the hand, thongs (I have done all of these) and you are back to square one. Yes. START OVER!

30 minutes and two changes of water later (which means three chances to ruin the print) the print can be hung to dry.

Once dried, it can be evaluated. Too light, start at the top and recoat for a second exposure. Doing a tri-color print? You are 1/3 of the way there (if you are very lucky). Oh, I forgot to mention, for multiple coats, the paper shrinks like cotton does and needs to be preshrunk at the beginning of the whole process to minimize this. That means a hot water bath and hand drying.

Are you exhausted just reading this yet?

The insanity of the process is what makes it so rewarding (maddening) I am starting to understand why so many great artists lose touch with reality.

Gumoil step test

The purpose of this test was to calibrate exposure for gum printing.

I used a 3:1 ratio of gum to sensitizer. 

The step chart goes from 100 black to 0 white in 20 steps.

I made 6 exposures from 30 seconds to 3 minutes in 30 second increments.

It was developed face down for 15 minutes with one change of water after three minutes. I then gave it a rinse with soft running water. It was put in the sun to dry before painting.

After drying, I applied a complete coverage of lampblack oil paint and then rubbed off with paper towels until it was a clear differentiation between exposed and unexposed gum. Then, after a quick soak to wet the paper, it went in a 15 second bleach. I used Clorox concentrated (8.25%) diluted to 6 percent and then mixed 1:6 with water. Another gentle rinse took it to this point.

The 30 second exposure was not enough to harden any of the gum. 1 minute showed hardening down to about 45 and 1.5 minutes down to 60. The highlights also cleared best at 1 minute.

I think about 4 more steps (of 20) were clear from the 1 minute exposure and 3 from the 1.5 minute exposure. Longer than 2 minutes, maybe only and additional step cleared and not very well. 

After drying, I attempted to apply a second coat of oil. To differentiate the two applications, I thought I would choose another color. I chose, Van Dyke Brown. I am not sure why, but it was a disaster. First it was very stick and hard to apply. Then, when rubbing it with paper towels, it pulled off paper, black oil paint and the kitchen sink. It was sticky like glue. When I rinsed it, it came right off without any bleach. Very strange indeed.i won't use that color again.

Anyway, I think that this has shown me that 1 minute to 1.25 minutes exposure works best. If less shadow is desired, the negative could be leveled to lift them to around 85 (from 100).

gumoil with halftone negatives test

Unfortunately I used negatives instead of positives (positives are required for gumoil prints to be positives). I think they look pretty good. The 50 lpi looks like it has better gradients than the grayscale. I am almost convinced, that for gum printing, halftone is the way to go.

From left to right: grayscale, 50 lpi, 25 lpi, 12 lpi halftone screens

gumoil prints

Here are a few gumoil prints of sunrise at Angkor Wat in Siem Reap, Cambodia

1.5 minute exposure. Highlights cleared in first bleach bath (etching) and then a coat of Payne's Gray.

2 minute exposure. I left this one in the bleach a bit too long and all the gum cleared. I left the highlights as they were.

45 second exposure. My favorite. The bleach cleared just enough for the second color (Payne's gray) to fill in. The second bleach then cleared the highlights in the clouds and the waterlilies.

Anyone who knows Angkor Wat will recognize that I forgot to reverse the positive before printing and ended up with a horizontally flipped image.

First try with halftone negative and gum

My first impressions are positive. The halftone pattern can easily be seen in the 12 lpi print.

Unfortunately the resolution of the emulsion is less than the resolution of the halftone screen past 12 lpi. Brushstrokes make it hare to see the pattern. That said, I think the 50 lpi halftone screen looks like is has better gradation of tones than the grayscale image (though the exposures were certainly not equal)

12 lpi halftone screen

25 lpi halftone screen

50 lpi halftone screen

Grayscale

 

More ideas

I want to try some things (things swirling in my head as I go to sleep)

1) gum print with film grain (iso 3200+) is the grain big enough to print and clear.

silver efex pro. ilford delta 3200 pro. maxed out at 1 grain per pixel and slider to "hard"

2) gum print with halftone dots. how big do the dots need to be to print

I have made halftone screens with frequencies of 6, 12, 25, and 50 lines per inch.

3) print step chart with gum oil. with exact measures, how much clears in 12 seconds? dry then re-etch. then duotones will be easier. need new bleach for this to be accurate.

4) gumoil with colored gum. in Karl Koenig's videos, his gum is easily visible. mine is too clear to see the etching easily.

Gum print test strips

My attempt at controlling variables.

These are 15sec increments to 1:15.

All of them with .3g / 4ml gum/sensitizer ratio

I settled on 45 second exposures as they were in the middle of the range for each color.

When I printed the tri-color print I used .2g/.3g/.6g per 4ml for C/M/Y respectively. 

The last one is a cyanotype test

First tri-color gum print

I am not sure about it. It takes a long time to get to here and it just must be better than this. Maybe another layer of yellow.

I used .2g/.3g/.6g per 4ml for C/M/Y respectively hoping to get the yellow and magenta to match the strong cyan.

First (semi) successful gum print

There are definitely more failures than successes so far. There are so many variables to this process that it is extremely important to be measured in what you have done. This was printed with Lamp Black (1.5g pigment/10ml gum arabic) and exposed for 1:30 minutes in bright sun. The highlights did not clear even after 30 minutes soaking in tepid water and needed to be aggressively sprayed to clear.

I am happy with the result but it is far from what can be called skill and still quite lucky.

I have just set up an Arista UV light source and can now be precise in the exposure.

Cyanotype Gelatin sized mulberry paper

The gelatin did a great job on sizing this paper. This paper was unusable (way too absorbent) as a base for emulsion without sizing. The cyanotype emulsion did not clear completely from the sized paper though, leaving a yellow color in the highlights. It was unexpected but not entirely undesirable.

Preparing Gum Arabic

I am using Gum Arabic powder for my gum prints.

This variable has got me stumped.

I have read ratios (g/ml of powder/water) from 16 / 100 ("28 grams gum arabic powder to 175ml of water") to 30 / 100 ("300g of gum arabic to 1000ml of water)

I also know that the commercial grade gum arabic in liquid form is 14 Baume.

I have made 10 prints at 16 / 100. The development stage is interesting. After 30 minutes of soak (2 refreshes of water) in tepid water the highlights have not cleared. But, with a directed stream of water, they loosen and clear quite quickly.

I am not sure why.

I also found this.

"SG (specific gravity)=145/(145-Bè)
If you substitute 14 for Bè then what you are looking for is a solution with a specific gravity of 1.106"

Since the Gum Arabic powder does little to the volume, the weight of 100ml (+the volume of gem arabic powder) should be110.6g. It seems to me that a little more than 10.6g of powder should do the trick.

Hmmmm.

Glass Cyanotype

I have been wanting to do this for a long time, but it seemed like a very difficult technique. In fact, it was quite easy!

The general idea is to coat glass with the same photographic emulsion used to make cyanotypes on paper. The problem to be overcome is that the emulsion has nothing to adhere to and would just run off the glass. The common solution is to use Gelatin as a size.

The gelatin was prepared by soaking 2 packets in 500ml of water for 15 minutes. It was then heated to 140-160 degrees Fahrenheit for 2 minutes. This was then mixed 1:1 with the standard cyanotype emulsion. I used 10ml of emulsion and 10ml of gelatin. This is poured onto a VERY carefully and completely cleaned glass plate. The emulsion is rolled around until the plate is coated. Amazingly, with careful tilting, the liquid does not roll over the sides. The excess liquid is poured off the corner of the plate back into the pot or into a paper towel. The plate is then set to dry. I have seen this process done under safelights, but as with paper, I did it under dim florescent light and the highlights cleared very well.

Once dry, the plate is exposed in very much the same way as a paper print.

The development is all done in water but clears very quickly.

I did a 30 second soak. When the plate came out and was set to dry, it ran blue chemical off into the paper towel. I think this is normal.

The second development bath is a bit more aggressive with light agitation.

A few beginnings: Sizing Paper

This weekend, I started a few new things.

Sizing paper:

Sizing paper is a technique that is used to prepare a substrate for coating with an emulsion. The Internet is full of examples of different chemicals and materials used for sizing paper. I started with three of them.

1) (simple) Acrylic Fixative - I only read this on one site, but it seems to make sense.

I tried this method with both Canson - feuilles fineface 190g watercolor paper and some handmade Saa Paper from Northern Thailand.

So far, I have only coated the paper for Cyanotype prints, but the Saa paper benefited the most with sizing really preventing the Cyanotype emulsion from sinking in to the fibers during coating and making it much easier (and more efficient) to apply.

2) (medium) Gesso + Water - I used a 1:1 mix of Clear Gesso and Water

I tried this method also with both Canson - feuilles fineface 190g watercolor paper and some handmade Saa Paper from Northern Thailand. I love the texture it leaves the paper. The Saa paper was almost completely sealed and took the emulsion well.

3) (complex) Gelatin - I used stock standard Knox Gelatine.

I have yet to coat these papers with emulsion. But the process of sizing with Gelatin was interesting and a good learning experience. The Watercolor paper was easy with a full submersion in a cookie tray of gelatin.

The Saa paper did not take well to being submerged in gelatin. It was too fragile to remove without damage. I resorted to using a brush on method with a soft hake brush. The paper was on glass and a saturated it then VERY gently squeegeed it off and hung it to dry.