allcolorlightblog-blog asked: wondering about double coating large gum prints with emulsion+pigment…waiting for first application to dry, then recoating. have you ever tried? does it sound like it would work or do you think that the pigment will fall out of the print?
I haven’t tried double coating. My sense is that it wouldn’t work as the second coat wouldn’t have anything to hold onto except the unexposed layer underneath and would most likely wash out when developed. Let me know if you have any success.
nonetodate asked: On your 1 Nov 2011 post concerning preparing “The Image for Multichannel” you mentioned you adjust the image for color balance (-35 Cyan and ? for Yellow). You also mention that you boost the saturation by 30%. On your 25 Jan 2012post regarding your “Gum Bichromate Workflow 2012” it states the Cyan layer is changed by -25 and saturation is boosted by 30%. Do you still modify the yellow by a certain %? Why do you do this on the image? Do you use the same amounts per ever image? Thanks!
I’m now going with the new adjustments of -25 C and +30 on the saturation and leaving the Y alone. I modify the image to compensate for how it changes after you apply the Multichannel so that the print ends up having the same saturation and color balance of the original image. Yes, I have been and will be using the same amount for every photograph.
nonetodate asked: I know you said that you use Glyoxal as your paper hardener. Do you use this straight or is it diluted? Also, how many coats do you put onto the paper and is it reapplied after a few coats of the pigment colors have been applied?
I mix up about 20 ml of 40% Glyoxal per liter of tap water and sometimes add ½ teaspoon of baking soda per liter. I use up to about a dozen individual layers of sensitizer and pigment. Staring with Magenta, then Yellow and Cyan, each layer takes about 1 ½ hours to coat, expose, develop and dry before I apply the next layer. I usually work on several prints at a time over the course of two days (aprox. 20 hours or so.)
fotodude asked: Hi Tony and thanks for sharing many of your Gum techniques. I do have two questions.1) It seems you use six layers for a gum print? Two cyanotypes plus yellow plus red plus blue pigment plus lamp black. If true why the “three” blue type layers and two passes with cyanotype? Your results are incredible.2) Do you develop the print in the “conventional” gum way by placing face down in water for 20 or 30 minutes? Thanks for any comments you provide. Terry Glass, Tipp City OH
Thanks for your interest in my process. Using the old cyanotype formula, I do two layers of cyanotype in the beginning to enhance the D-max in the print as well as to add detail (one layer of cyanotype may be fine too). Afterwards, I add the layers of gum with magenta, yellow and cyan (three layers with each color). Although some of my students stop after the second layer of M, Y & C, I prefer a third layer for deeper shadow tones and greater depth in the print. I do still development face down for no more than 30 minutes.
allkimik asked: Hello Sir, you cannot imagine the energy and the momentum that this blog fed me last weeks. I wasn’t so pleased with my experimentations with gum, but after reading your material it was like a fresh start for me. I still do some stuff that I found out on my own, and I print my negatives on plain paper. Here in Romania the acces to materials is very difficult. And here come the question: what paper do you like the most? What papers did you used during the many years of doing this? Thank you a lot
Thanks. Since I started printing gum over ten years ago, the paper I’ve been using (and continue to use) is Rives BFK, white, 250 grams, mould-made, 100% cotton, PH neutral, 22×30. It’s available at New York Central in Manhattan. http://www.nycentralart.com
Pigment: Winsor & Newton Professional Watercolor, Lamp Black
Winsor & Newton Designers Gouache, Lamp Black
Sensitizer
I use Ammonium Dichromate for the sensitizer. Working with the 1:1 ratio as a starting point I use 12 “droppers” (as much solution of either gum or sensitizer as the stem of the dropper can hold) gum arabic to 12 “droppers” of sensitizer (for a total of 24 “droppers”) with about ½ inch to ¾ inch “worm” of pigment (*only about ¼ inch for gouache). Altering the ratio (even slightly, for example: less droppers of gum to sensitizer–i.e. 10 droppers of gum to 14 droppers will produce less contrast and more drops of gum to sensitizer will produce greater contrast (i.e. 14 droppers of gum to 10 drops of sensitizer).
Making the Print: Cyanotype
I use Cyanotype as the first layer to add detail and enhance the D-max. I do a 20-minute exposure (enough to achieve tone in step #3) before any gum layer is put on.
Making the Gum Print: Coating
After the Cyanotype layer, I start with a short exposure to produce tone no greater than step 2/3 to establish the shadows. My exposure for the first set is 1 minute 30 seconds (at a 12 droppers gum: 12 droppers sensitizer ratio). The seconds set is longer at 6 minutes 30/45 seconds (at a 13 droppers gum: 11 droppers sensitizer ratio) and produces tone up to step 8 to establish the mid-tones and highlights. For more density in the shadows, I then add a short exposure (at a 14 droppers gum: 10 droppers sensitizer ratio) for about 2 minutes (for no greater than step 3). Finally, to add a little “kick” to the shadow and give more depth to the print, I use lamp black gouache (at a 15 droppers gum: 9 droppers sensitizer ratio) as a final layer with a 30 second exposure time (no more than step 2).
Making the Gum Print: Development
I “still” develop the FIRST SET in a tray of water (about 68-75 degrees) for about 5 minutes until the boarders of the print start to clear–then in a second tray with cold water for about 10-15 minutes and change to cold water (warm water as needed) at 5-minute intervals for a total of 30 minutes development time. For the SECOND SET (as well as any additional sets), I still develop in a tray of water (about 68-75 degrees) for about 5 minutes until the boarders of the print start to clear then in a second tray with cold water (warm water as needed) for about 10 minutes and change water at 5 minute intervals for a total of 30 minutes development time. After each exposure, I also immerse the print in a tray of 1% Potassium Metabisulfite solution to keep the boarders white.
Making the Print: Workflow (exposure times may vary)
· Layer #1Cyanotype – 10ml of each A/B Cyanotype chemistry. Exposed 20 minutes (enough to achieve tone in step #3).
· Layer #2Gum Bichromate Lamp Black Watercolor – at 1:1 gum to sensitizer ratio (12 full eyedroppers of gum and 12 full eyedroppers of ammonium dichromate). Expose for 1 minute 30 seconds (enough to achieve slight tone in step #3) and “still” developed for ½ hour in cold/warm water.
· Layer #3Gum Bichromate – Lamp Black Watercolor – 13 full eyedroppers of gum and 11 full eyedroppers of ammonium dichromate. Expose for 6 minutes 30/45 seconds (enough to achieve slight tone in step #8) and “still” developed for ½ hour in cold/warm water.
· Layer #4Gum Bichromate – Lamp Black Watercolor – 14 full eyedroppers of gum and 10 full eyedroppers of ammonium dichromate. Expose for 2 minutes(enough to achieve tone in step #3) and “still” developed for ½ hour in cold/warm water
· Layer #5Gum Bichromate – Lamp Black Gouache ONLY A QUARTER INCH OF PIGMENT– 15 full eyedroppers of gum and 9 full eyedroppers of ammonium dichromate. Expose for 30 seconds (enough to make step #2 disappear) and “still” developed for ½ hour in cold water.
