We are testing the effectiveness of BIG (Baldwin Intaglio Ground) hardground in our Copper Sulfate mordant.
Date: February 11, 2011
Researcher’s Name: Chelsea Mullins and Melissa Mandel
Plate Material: .040 Zinc
Plate Size: 5 in x 7 in
The plate was degreased with soy sauce that was rubbed onto the zinc plate using a piece of rolled felt, rinsed and then dried with a clean rag and blow dryer. The BIG was squeezed from the tube onto a clean, glass inking slab, spread with a knife and rolled up using a 4″ diameter, medium hardness brayer. Several thin layers of red BIG were rolled across the surface of the zinc plate, building gradually to the point that the zinc did not sparkle through the ground. We dried BIG in the hotbox for 25 minutes or until it was smooth to the touch without any tack. Using etching scribes and a roulette we drew through the ground and completed our image. The drawn lines were originally needle thin. Red sharpie permanent marker was used to stop-out the edges of the plate.
The Copper Sulfate Mordant consists of 50gm salt + 50 gm copper sulphate + 1 liter H20 stored in a plastic lidded container. We created a shallow bath in a plastic tray where we can place the zinc plate for etching.
Timed Application of Mordant
After 1 minute 30 seconds the sharpie areas started to etch. 7 minutes 30 seconds ground is holding up well as we use a sponge to wipe away zinc debris out of the etched lines. 10 minutes 20 seconds the lines begin widening. 15 minutes the lines are much wider. 18 minutes we can feel the edges of the etch with our sponge. 20 minutes foul biting and larger spots are loosing detail in roulette areas.
Removal of Grounds
We used DeSolve to remove the BIG ground but the smell is too strong.
After Bath Evaluation
The plate looks over etched.
The plates were inked with unmodified Graphic Chemical & Ink Co. Bone Black Etching Ink #514. The ink was carded on with mat board scraps, wiped with used tarlatan, and then palm wiped.
Paper Type: Hahnemule Copperplate
Paper Soaking Time: 15 Minutes
Press Blanket Setup: Sizing catcher and pusher, 10.2 pressure, Small Takach Press
We lost detail in the roulette areas and foul biting created a texture in the background. All lines are wider than originally desired.