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.
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