In this test, we aimed to obtain a specific measurement of Gum Arabic, and use this measurement as a baseline for other tests. We suspect that in the last test what we estimated to be 1 tablespoon was actually much less. Also, we wished to use a more recognizable image so that we could better evaluate the fidelity of the proof to the initial photocopy. To this end we chose to use a portrait.
Date: September 20, 2012
Researcher’s Name: Kayla Biggs and Sally Mackenzie
Plate Material: .032 Copper
Plate Size: 4″x6″
Room Temperature: 69 degrees F
We degreased the plate with alternating applications of Bon Ami and soy sauce, rubbed on with gloved hands. We then rinsed the plate under water, deoxidized (in a solution of 1 gallon white distilled vinegar to 1 cup salt) and dried with newsprint.
Next, we prepared a 4″ by 6″ photocopy from a black and white source photo. We then measured 1 tablespoon of Gum Arabic and used our hands to spread it evenly onto a piece of glass. There were some small puddles. We used this excess to rub into the surface of the photocopy, atop the gummed glass.
Meanwhile, we mixed approximately one teaspoon of red BIG with a pea-sized amount of tack reducer. We then rolled the prepared BIG over the gummed photocopy. The buildup of Gum on the surface of the copy made it difficult to roll on the BIG. The photocopy stuck to the roller initially, and wrinkled, causing a crease that would not hold BIG. It took several rolls to get any BIG to adhere. Only after thoroughly coating the photocopy in B.I.G, we focused on sponging off the BIG thoroughly and evenly to eliminate blotches. In our previous experiments, these thickly grounded spots had resisted the ferric and produced white patches in areas that should have been dark.
Next, we stuck the photocopy face down on the prepared copper plate. We ran it through the Takach press with two sizing catchers and two pieces of newsprint, on 5.5 pressure.
When we removed the plate from the press we were impressed with the transfer. The image was clearly recognizable, and appeared to have nice detail and tone.
We prepared the plate for etching by backing it with contact paper and applying Sharpie to the edges. We then etched the plate for 30 minutes in 41 deg Baume Ferric Chloride.
Timed Application of Mordant
Removal of Grounds
Ground lifted readily almost immediately after etching. We rubbed the majority of it off in the stripper solution with a gloved finger, and took care of the rest with two sprinkles of Bon Ami, then a single spritz of Soy Solv to finish the job.
After Bath Evaluation
Or plate had clearly etched, and we were pleased to see that areas where BIG had transfered looked like etched aquatint, finer and less mottled than in the previous trials. Areas allowed to open-bite had a slight texture and streaky appearance, but were still relatively smooth, though these might benefit from some polishing.
We applied Graphic Chemical Bone Black oil-based ink to the warmed plate with a mat board chip, then wiped with tarletan in circular motions until most of the ink was removed. We then cleaned the edges with a cloth, and did a palm-wipe using whiting.
Paper Type: Hahnemuhle Copperplate
Paper Soaking Time: 30 minutes
Press Blanket Setup: Takach press, 2 sizing catchers, one piece of newsprint, pressure 5.5
We had exciting results with this test. While the print has very little tonal variety, we achieved sharp, accurate edges, some (not all) of the photocopy’s finer details, and rich, even tone overall. The BIG acted more like an aquatint this time, joining with the Gum Arabic to allow a cleaner, finer texture to etch into the plate. Our notion is that this finer dot pattern is the result of a more calculated ratio of Gum to BIG, and a somewhat more thorough sponging of the treated photocopy prior to transfer. At this point we believe that a full range of tone may not be feasible with this process, that it may work best with higher-contrast images. We are very happy with the level of detail in this print, particularly of facial features. Still, line-like detail that appears white in the original photocopy (the edge of the cake plate, specifically) holds ink and prints black, a problem we also saw in our previous tests. We wonder if this could be remedied by more attention to these details in the sponging stage. Finally, we’d like to prevent damage to the photocopy in the rolling stage, like the diagonal crease through the center of the image. We wonder if this could be helped by photocopying onto a heavier paper, and/or rolling on BIG from the center of the paper, rather than the bottom edge.