February 5, 2015 (printed 2/5)
Researchers: Audrey Blood / Jenny Gover
Room Temperature: 68 degrees F
Materials: Pledge Floor Care Finish, Speedball India Ink, Golden GAC-100, Golden airbrush medium, Golden flow release
Abstract: Creating a denser color for Edinburgh Mix #6
Edinburgh Mix #7 (plate 19)
10 tsp Pledge Floor Care Finish
1.5 tsp Golden GAC-100
3 drops Golden Flow Release
3 drops Golden Airbrush Medium
4 tsp Speedball India Ink
We mixed the ingredients together in a small container, adding the Pledge Floor Finish last. The mixture was sprayed through the Badger airbrush on the finest setting onto a 4.5″ x 6″ copper plate at a distance of 6 to 8 inches with approximately 20 passes with the spray barely visible coming out of the airbrush. We then opened the airbrush just slightly and sprayed a additional 4 passes over the plate. It was set in the drying box for 20 minutes.
The plate was step-etched on 1/20 in 38 degree baume ferric chloride. It was placed in the stripper bath of 3 cups washing soda to 12 liters of warm water for 10 minutes, rinsed, dried, and printed.
When we compared Edinburgh Mix #6 to Edinburgh Mix #6 on a draw down sheet, it was clear that the additional tsp of India Ink in Mix #7 created a much denser color without compromising the viscosity of the mixture. The mixture was sprayed evenly through the airbrush without any clogging or sputtering. We discovered that once the airbrush was set down for a few minutes after being sprayed it needed to be reopened and sprayed before it can be tightened and sprayed on the finest setting again.
The ground came off easily after etching with approximately 10 minutes in the stripper bath.
We printed on a Takach press using 2 sizing catchers at 4.5 pressure. Ink: Charbonnel #55981 oil-based etching ink with 2 drops 00 plate oil. Paper: Hahnemuhle copperplate white. After printing plate 19 three times, we were unable to get a fine, even toned print, and decided that the plate was over sprayed. When we compared the newsprint spray for plate 19 with the newsprint spray for plate 16 (our most successful print so far), it was evident that the airbrush was on a finer setting for plate 16, creating a much more even spray.