Creating an Acrylic Spray Aquatint Test 17

February 19, 2015 (printed 2/19)
Researchers: Audrey Blood / Jenny Gover
Room Temperature: 67 degrees F
Humidity: dry
Materials: Pledge Floor Care Finish, Golden GAC-100, Golden airbrush medium, Golden flow release, Speedball India Ink
Abstract: Re-spraying Edinburgh Mix #7 and creating a replica for Z-Acryl Stop Out

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Edinburgh Mix #7 (plate 20)
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

Stop Out Mix #1
1/2 tsp GAC-100
1/2 tsp Pledge Floor Finish
5 drops Speedball India Ink

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Procedure:
Edinburgh Mixture #7 sat in its container for 14 days, was stirred gently, and then 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. It was set in the drying box for 20 minutes.

We then made a Stop Out mixture of 1 part GAC-100 to 1 part Pledge Floor Finish with 5 drops of India Ink as a colorant. We then painted this mixture onto the right side of the sprayed aquatinted plate.

The plate was step-etched on 1/20 in 37 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.

Ex_17_01
comparison of stop out mix #1 and Z-Acryl stop out on paper

spray_plate20
spray of Edinburgh mix #7 onto newsprint

Conclusions:

Mixture
The Edinburgh Mixture #7 held up well for the 14 days that it was in the container, needed just some stirring to be well mixed. There has been no marked change to the mixture or the spray. We were cautious not to overspray this plate, and used the newsprint from plate 16 as a guide.

The stop out mixture is looser than the Z-Acryl Stop Out and dried much faster. It flowed easily when painted onto the plate without bleeding into unwanted parts of the plate. On the draw down sheet, the color is not as dense as the Z-Acryl and could possible use more India Ink to be visible on the plate.

Stripping
The ground came off easily after etching with approximately 10 minutes in the stripper bath.

Printing
We printed the first print on a Takach press using 2 sizing catchers at 4.5 pressure and the second print on a Takach press using 2 sizing catchers at 5.0 pressure. Ink: Charbonnel #55981 oil-based etching ink with 2 drops 00 plate oil. Paper: Hahnemuhle copperplate warm white. The aquatint printed very fine and dark, with an even tone. The areas of the plate that had been covered with stop out were clean and bright. Unfortunately, after stripping the aquatint and stop out off of the plate, we accidentally left the plate in the deoxidizer bath of salt and vinegar for over an hour. While this did not have too much of an effect on the quality of the aquatint, it did have an effect the open areas of the plate where the stop out had been. They appear light grey in the print, whereas they should have been clear and white.

plate20_spray
print of plate 20

Creating an Acrylic Spray Aquatint Test 18 >