Test Summary
For this trial, an additional set of adjustments were applied to the image through the “Levels” Image Adjustment, in hopes of obtaining a more varied tonal range.
Date: June 18, 2013
Researcher’s Name: Liz Bannish and Stephanie Gaumond
Plate Material: Copper 0.32″
Plate Size: 4 x 5.25″
Room Temperature: 70° F and very humid
Plate Preparation
The plate was beveled, polished with 00 grade steel wool, and degreased with 1:1 soy sauce: water ratio.
The image size was changed from 72 ppi to 300 ppi.
The image was inverted first.
Color Balance: Highlights- Cyan= -31 Magenta= 0 Yellow= -26. Shadows- Cyan=0 Magenta=0 Yellow= 0
Channel Mixer: Monochrome box checked
The new adjustment, “Levels,” (Under Image> Adjustments> Levels), was added and given the following values: Black= 25, White= 225.
Curves: Black=45 White=225. Two middle points: Output 62/Input 64 (the gray-black) and Output 171/Input 175 (the gray-white).
Aquatint screen filter= 50%, Relief 24%
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
The Photoshopped image ready to print
Etching Notes
Ferric Chloride 41 degrees Baume
Timed Application of Mordant
30 minutes
Removal of Grounds
Ground removed with Soy Solv Industrial Cleaner and rag and a toothbrush.
After Bath Evaluation
Etched well, slash marks are evident in some areas.
Inking Methods
Plate inked with Graphic Chemical Etching Ink in Bone Black
Paper Type: Hahnemuhle Copperplate
Paper Soaking Time: 10 Minutes
Press Blanket Setup: Charles Brand Press with 2 blankets, at 0.6 pressure
Test Conclusion
The plate printed with the best blacks we have achieved so far, however, the slanted hatch marks are back where the light and mid grays should be. Some graininess exists in these areas as well. The areas of the image with the lightest highlights have retained their whites, but transitions of tone are rough and much detail is lost. In a future trial, if levels are still to be included then perhaps testers need be more prudent with the white values. Instead of white being at 225 (darker), perhaps it should be upped to a higher (lighter) number.
Printed Images
Top to bottom: film positive, etched plate, final printed image.