With this particular test we focused on the scaling adjustment within the aquatint screen we scanned in and are currently using as our filter. We did an additional test considering the dpi of the printer after our initial scaling test.
Date: June 11, 2013
Researcher’s Name: Liz Bannish and Stephanie Gaumond
Plate Material: .032″ Copper
Plate Size: 4″ x 5.25″ (tonal 4×2″)
Room Temperature: 72 degrees Fahrenheit
The plate was beveled, polished with 00 grade steel wool, and degreased with 1:1 soy sauce: water ratio. The PCB film was prepared for two images: one image being the current image in question from the last several experiments, and the other, a value scale to clarify which tones of the image are problematic. We are looking out for graininess and amount of variance in tone from the mid-grays to the lighter white gray. Both images have the same parameters:
The images was inverted first.
Color Balance: Highlights- Cyan= -31 Magenta= 0 Yellow= -26 Shadows- Cyan=0 Magenta=0 Yellow= 22
Channel Mixer: Monochrome box checked
Curves: Tried new values. Black=45 White=225
Aquatint screen filter: brought to its lowest possible scaling= 50%
Print Parameters Used Let Photoshop determine the colors. Gray Gamma 2.2. Rendering intent=Perceptual. Presets= Our earlier Press-n-Peel with Plain Paper Resolution HQ 1200
Ferric Chloride 41 degrees Baume
Timed Application of Mordant
30 minute etch
Removal of Grounds
Ground removed with Soy Solv Industrial Cleaner and rag and a toothbrush.
After Bath Evaluation
Plate etched well.
Plates inked with Graphic Chemical Etching Ink in Bone Black
Paper Type: Hahnemuhle Copperplate
Paper Soaking Time: 10 minutes
Press Blanket Setup: Press: Praga Pressure: 4.0 Blankets: 2 thin blankets
The images are still grainy but less so than last time. Whites are very white and there is more detail held in the blacks. however, mid-tones are still stagnant; in the value scale all of the mid to light grays are the same tone. With the change in the printer resolution the hatch marks are back – clearly the result of the printer settings. While the image quality is poor the tone of the blacks are rich. We didn’t get any open biting despite the change in number of dots put down by the printer. This leads us to believe that we can push the values more within the curves setting because the change in tonal quality is desired and possible as we can see with this trial. The scaling of the filter better at the lowest possible setting.