Sandpaper Aquatint with BIG Ground Test 11

Test Summary
This test we will use 400 grit sandpaper to create an aquatint impression. We etched the plate 2 times creating 15 and 30 minute step bitten areas.

Date: December 2, 2011
Researcher’s Name: Andrea Santos and Laura Sheys
Plate Material: .032 copper
Plate Size: 3″ x 4″
Room Temperature: 72, low humidity

Plate Preparation
The copper plate was polished with Putz Pomade, steel wool, and a scraper to remove large marks. The plate was degreased with soy sauce that was rubbed onto the copper plate using a piece of rolled felt, rinsed and then dried with a clean rag and blow dryer. The BIG ground was applied using a hand roller and hardened in the oven at 220 degrees for 10 minutes. On the plate we laid 400 grit sandpaper face down and ran it through the etching press for a total of 8 times. After each pass we slightly turned the sandpaper in a clockwise motion to ensure an even impression. We rinsed the plate well under running water and the surface feels slightly course. There was a 1:3 ratio of exposed copper to ground on the plate.

Etching Notes
The plate was rinsed well under-water after prepping the aquatint at the press. The plate was etched in a vertical etching tank of 38° Baume Ferric Chloride for a total of 30 minutes.

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Timed Application of Mordant
The copper plate was etched two times. After the first 15 minutes we took the plate out of the bath, rinsed it under running water, and placed it in the brightener bath to remove oxidation. After we dried the plate with a clean rag we stopped out half the plate areas with clear packing tape. We placed the plate back in the bath to etch for an additional 15 minutes.

Removal of Grounds
The ground was removed with a clean rag, Soy Solve, and Simple Green. After we removed BIG the plates were rinsed in water and deoxidized in the plate brightener bath made of distilled white vinegar and salt (1 gallon/1 cup). It took a few applications and a toothbrush to scrub the ground completely off.

After Bath Evaluation
The first 15 minutes of etching caused the ground was flaking off especially near the edges. After 30 minutes of etching the plate’s edges showed signs of false biting, but the surface of the grounded plate remained intact. The red of the ground is significantly darker in the 30 minute section.

Inking Methods
The plate was inked using Daniel Smith Creamy French Black thinned with a drop of #00 burnt plate oil. The ink was carded on with mat board scraps, wiped in gentle circular motions with used tarlatan, and then palm wiped.

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Paper Type: Hahnemuhle Copperplate
Paper Soaking Time: 20 minutes
Press Blanket Setup: 2 blankets, 7.5 pressure, small tabletop Takach press

Test Conclusion
Deoxidizing the plate before adding the packing tape for the full 30 minutes of etching produced better results. The 15 minute area is a true medium grey and the 30 minute section is a rich black. After inking the plate the variation and discoloration disappeared and the printed proof turned out smooth and even. The variation in the plate didn’t translate to the printed proof.

Printed Images

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Sandpaper Aquatint with BIG Ground Test 12 >