September 24, 2015
Researchers: Stephanie Motyka, Kristina Key
Room Temperature: 71º F
Humidity: low humid
Materials: Copper, Soy Wax Soft Ground (Soy Wax & Litho Ink), Zea Mays Acrylic Stop Out, 15º baume ferric, 20º baume ferric bath, different mark making tools for drawing textures.
Abstract: Testing with a stronger ferric bath(s) to see how soft ground will hold up and whether or not it will etch in a quality that is similar to 12.5º baume ferric.We tested 15º baume and 20º baume.
Soy Wax Litho Ink Soft Ground Mixture:
55% Soy Wax and 45% Lithographic Ink (found in previous tests for this research)
To create the stronger ferric bath(s), we altered the 12.5º baume ferric to suit our needs. The 15º baume was already created from the 12.5º baume ferric evaporating slightly since last use. This is why it is important to always check the baume of the ferric for accurate measurements.
We mixed the 20º baume ferric by modifying the 12.5º baume with the 36º baume ferric from the vertical etching bath. It was best to just take the 36º out of the tank and use that because a new ferric would need to be cured. New ferric is strong and would throw off our test.
We placed the plate on a hot plate and rolled the soft ground on it with a brayer until it was evenly coated then added a variety of marks to the soft ground.
The stage biting increments were 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, and 40 minutes. Each increment was stopped out with Zea Mays Acrylic Stop Out. It was necessary to put down two coats of the stop out with drying in between each. This helped prevent foul biting in the bath during the next etching stage. We noted that foul biting in the stop out started during the 30 minute etch in the 20º baume ferric as well as the 15º baume.
The 15º baume ferric etched quickly and the soft ground held up throughout the entire time. I had to touch up a couple spots each time the plate was removed from the ferric with stop out. The plate was printed on a Takach etching press with the pressure at .6 with two sizing catchers, Graphic Chemical 514 Bone Black ink, and Hanemuehle Copperplate paper that was soaked for 15 minutes.
The 20º baume ferric etched seemingly fast and strong. Areas with wide marks took more stop out to cover completely. The thick areas also seemed to open bite a bit due to the wide and deep area.Other than that, the plate etched bold lines and various tones from different marks.