The Refined Gum Print ~ Viscosity Matters

The last post was on gum printing when I was just beginning to learn the process. Therein also lies a lesson almost exclusive to gum printing, i.e. no one knows what you intended, thus whatever you have, if it has any visual equity, could be a finished print, if you like it. The gum print of the last post is an example, being it is not what I was after, yet the outcome was visually appealing to viewers. Whether a print should be seen by eyes other than your own is one of those personal choices printers make.

What was obvious about that gum print (9/24) was the more vibrant and distinct color layers of the  print. They didn't overlay or meld their transparencies to form an additional color (2 colors added to create a 3rd), they remained mostly distinct. In subtractive color layering, two, or more, thin translucent color layers will combine to create an 'added' color. For example, a magenta color layer followed by a yellow color layer leaves orange of some shade, depending on the amounts of each color applied. By adding a cyan layer over the same magenta layer results in a warm, or cool brown tone, again depending on the amounts of each color layer.

This is a form of mixing an additional color layer palate of colors during each printing. The pigment amount of each layer adds to and alters the resultant colored image. That is the primary control, beyond the selection of sizing & mixture levels. The gum print is shaped many ways during the actual printing, at each juncture of control; paper choice, sizing, gum viscosity, pigment type and amount applied, length of print time and floating time, each layer. There is much room for personalizing an image.

This print was the final print I made back then. I had learned a number of these controls and their visual outcomes behind me, however I was still using paper negatives at that time. I had tuned the mixtures to better accommodate each other for my printing method. I was working to achieve a print with a fuller tonal range and better separation, as well as increased textural detail. That meant cutting back on sizing amount and increasing gum viscosity. The paper was working out well.

It is fairly easy to see the differences between the two print outcomes. Separation of tonal values and textural detail can be achieved even with a paper negative, however, that entails very close scrutiny of printing and float times to achieve any success. Not every color layer was a full page coating. One such coating was applied locally, using six small cups of gum mixtures, each with a bit different color mixed, from a dark Forest Green mixture to lighter green to yellow-green to yellow. Each of these colors were applied locally to leaves and other portions of the background trees, using a loop and a very tiny pointed brush. The final layer was a 'golden' color, to my eye anyway, applied as a very thin shear layer, then floated off of the highlights, leaving a sort of golden tone to the lower tonal ranges, in an attempt to mimic the late afternoon "golden glow". I leave it to the viewer to decide if I was successful.

Process: Arches 140lb hot press watercolor paper:
Pre-shrink paper ~ Water @ 120 deg; soak paper minimum 30 secs ~ dry paper
Sizing; (2) coats sizing;  2 1/2% solution Knox Gelatin @100 deg ~
Gum Mixture; 50% mixture ~ (50g gum Arabic to 100ml distilled water)
(13) Print layers of translucent colors