Sodium Alginate Acrylic Hard Ground: Experiment 4

Acrylic Sodium Alginate Hardground: Experiment 4, 1:96 week old vs 1:96 fresh
Researchers: Zoe Dong and Megan Ogden
Date: 9/27/2018
Temp: 72 degrees
Humidity: cloudy day, high humidity

After seeing the results of the prints from experiment #3, we decided to test a week old 1:96 sodium alginate acrylic hard ground and a freshly made 1:96 hard ground.

First, we mixed up ⅛ teaspoons sodium alginate with 4 tablespoons ZMP stop out and let it sit for 1 hour. During that hour we mixed it periodically. Our observations of both mixtures are below:

Mixture Observations
Week old 1:96 Smooth consistency, all lumps are gone, Flows nicely and is thicker than the stop out.
Fresh 1:96 Some lumps and inconsistent consistency. Thicker than stop out, not as silky smooth as the week old mixture.

Clumping in the fresh 1:96 mixture

 

After our fresh mixture sat for an hour we prepared two copper plates by beveling all edges, buffing the surfaces using first a scouring pad followed by steel wool, then we degreased them using Bon Ami and soy sauce. After our plates where buffed and degreased, we applied the week-old 1:96 and fresh 1:96 as follows:

Plate #1: Convection oven at 275 for 8 mins

Week old 1:96 sodium alginate acrylic hardground brushed on with foam brush
Fresh 1:96 sodium alginate acrylic hard ground brushed on with foam brush

Plate #2: Air Dry

Week old 1:96 sodium alginate hard ground brushed on with foam brush
Fresh 1:96 sodium alginate hard ground brushed on with foam brush

We attempted to brush on as thin a layer as possible, but still have full plate coverage. We did this by brushing across the surface of each plate a couple times to smooth out brush marks and remove accesses ground. It took around 20-40 mins for both plates to air dry and 8 mins in the convection oven.

 

A brushed on plate

Air drying the brushed on plates

Crackling as a result of baking in convection oven

 

Once dry, we drew into both plates using an etching needle. Drawing into the convection heated plate felt plasticky and ripped the ground making it harder to draw through than the air drying plate. The marks made on the air dry plate were crisper and consistent compared to the convection heated plate.

After drawing into the plates we step etched them in segments of 5, 15, 45 and 60 mins in a ferric chloride bath with a balmate of 38. We layed out the step etching so that on each plate, both the week old and new hard ground would be step etched with the same times.

After 5 minute etch. On Left; Heat set 1:96 week old ground on top, day of ground on bottom. On Right; Air dry 1:96 week old ground on top, day of ground on bottom.

Some biting occurs on plate

After 15 minute etch. On Left; Heat set 1:96 week old ground on top, day of ground on bottom. On Right; Air dry 1:96 week old ground on top, day of ground on bottom.

After 60 minute etch. On Left; Heat set 1:96 week old ground on top, day of ground on bottom. On Right; Air dry 1:96 week old ground on top, day of ground on bottom.

After etching we stripped the plates in sodium carbonate. The plate that was heat set took twice as long to strip, about 30 mins total.

Once stripped we inked and printed the plates using the following:
Paper: Hahnemuhle Copperplate
Ink: Graphic Chemical INK CO Bone Black #514C oil based etching ink
Modifier: Linseed oil
Wiping: Tarlatan and newsprint

We modified the ink very slightly and carded the ink onto the plate with matte board and then wiped both plates using tarlatan followed by newsprint to remove any residual plate tone. We soaked the paper Hahnemuhle copperplate for 15 mins then blotted it dry between two towels before printing.

The results of the prints were showed the difference between the two different drying methods and the age of the hard ground. The skipping and difficulty of drawing through the convection heated plate is evident in the thickness and inconsistent printed marks. There is a subtle difference between marks made in the week old hard ground and those made in the fresh ground, but it is evident that the lines are sharper and slightly more consistent in the week old hard ground. We hypothesize this is because of the smooth quality of the week old mixture; the lumpiness of the new stop out made the etching needle grab the ground instead of drawing through it.

Top plate is air dried. Bottom plate is heat set.

 

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