Creating an Acrylic Spray Aquatint Test 6

November 6, 2014 (printed 11/18)
Researchers: Audrey Blood / Jenny Gover
Room Temperature: 63 degrees F
Humidity: average to dry
Materials: Golden GAC-100, Akua monotype ink Jet Black, Golden airbrush medium, water
Abstract: Attempting a spray aquatint mixture using Golden GAC-100 (Part 3)

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GAC-100 Mix #3 (plate 6):
6 tsp GAC-100
4 tsp Water
1 tsp Akua  jet black monotype ink
3 drops Golden airbrush medium

GAC-100 Mix #4 (plate 7):
8 tsp GAC-100
2 tsp Water
1 tsp Akua jet black monotype ink
3 drops Golden airbrush medium

Procedure:
We decided to switch from measuring in ounces to measuring in teaspoons in order to make more precise, smaller mixtures. After etching plate 5, which had a ratio of 3:1 GAC-100 to water with Akua ink as a colorant, we decided to make two more plates with the same ingredients and different ratios of GAC-100 to water in order to see how much the GAC-100 could be diluted. We mixed ingredients together in small container. Sprayed through Badger Airbrush on finest possible setting onto newsprint. The plates were sprayed at a distance of 6-8 inches with approximately 15 passes. They were set to dry in the drying box for 20 minutes, then removed and sat grounded in our drawer for one week before etching. They were then step-etched in 39 degree baume ferric chloride. The plates were stripped first with the stripper bath and finished with SoySolv II spray. They were then printed three times.

experiment6_01
measuring mix 3 and mix 4 in teaspoons 

experiment6_02
mixing in Akua jetblack monotype ink 

experiment6_03
mix 3

Conclusions:

The Mixture
It was difficult to see whether the GAC-100 mixed in thoroughly with the other ingredients. The mixtures had a similar viscosity to Z-Acryl. When we first sprayed these mixtures through the airbrush, it was hard to see whether anything was coming out. We decided to clean the airbrush before proceeding. Thoroughly cleaning the airbrush required at least 3 changes of water in order to remove all of the stuck ground. This may have been accumulating throughout our previous experiments as well. After putting the airbrush back together and spraying again, it was still difficult to see the spray on the newsprint. Looking through a loupe, we were able to see that an even spray was in fact going onto the newsprint. This was the only way that we were able to judge whether our plates were properly covered.

Stripping
These plates were very difficult to strip. We left the plates in the stripper solution for 20 minutes, but this did not seem to remove the ground at all. Next, we soaked the plates in SoySolv II for an hour. Both plates still felt like they had ground remaining. Plate 7 also produced a white foam when rubbed. We printed the plates once, and still were not confident that all of the ground had been removed, so we cleaned them with SoySolv II again and then deoxidized them in a salt and vinegar bath.

Looking at the plates
Looking at the plates with a loupe, we were able to see that we had been wrong. The ground had not in fact stuck to the plates, but rather had fallen off in the acid at longer etch times. We then compared plates 5, 6, and 7 with plate 3 (our best aquatint so far), and we could see that all of the GAC-100 plates had lost their ground at longer etch times, causing large areas of open biting. We had mistaken the roughness of these patches with what we thought was stuck ground.

Plate 5 had a more evenly printed aquatint than plate 6 and 7. However, looking at the newsprint for plate 5, it is clear that the plate was over-sprayed because the ground was difficult to see on the newsprint and on the plate while being sprayed. We think that because plate 5 was over-sprayed, it did lose ground in the etch, but this was not as evident as with plates 6 and 7 because the over-sprayed ground compensated for the ground that did come off.

experiment6_05
plates 4, 5, 6, and 7

Printing
We printed on a Takach press using 2 sizing catchers at 6.5 pressure. Ink: Charbonnel #55985 oil-based etching ink with 2 drops 00 plate oil. Paper: Hahnemuhle copperplate white. The first set of prints were coarse and the pressure was too light. We decided to try printing at 5.5 pressure with Charbonnel #55981 oil-based etching ink with 2 drops 00 plate oil in order to see if the stickier #55985 was causing the coarse aquatint when printed. When using the looser #55981, however, the aquatint still printed coarse and uneven. This supported the theory that the ground was actually coming off of the plate in the etch, and the coarse print was not caused by the pressure or the #55985 ink.

plate_06
plate 6 printed

plate_07
plate 7 printed

Creating an Acrylic Spray Aquatint Test 7 >