For this test, the images were prepared in Photoshop exactly the same as the previous test 9, however, with the difference being the dpi output for the printer. From the last test, it was concluded that image set at 600 dpi was more successful than the HQ 1200. Therefore, the next two plates show images at both 600 and 300 dpi. They are also inverted, a crucial step testers missed during the last trial that may have affected the outcome more than they thought. Plates are regarded as Plates 22C and 22D, as a Part II to Test 9 of Plates 22A and 22B.
Date: May 3, 2013
Researcher’s Name: Liz Bannish and Stephanie Gaumond
Plate Material: Copper .032″
Plate Size: 6″x6″
Room Temperature: 71
Plate was backed with contact paper, beveled, polished with 00 gauge steel wool, and degreased with a ratio of 1:1 soy sauce to water.
Image was opened in Photoshop. The channel mixer was opened under Image>Adjustments>Channel Mixer. In the Channel Mixer menu the “Monochrome” box was checked to give the image an appearance of black and white, even though it was technically still being profiled as RGB. In the Channel Mixer the sliders were adjusted to bring all values in the image just about down to a middle gray. Red: +74, Green:+18, Blue:+2.
A new adjustment layer was added and the shadows, midtones, and highlights were adjusted under Image>Adjustments>Color Balance.
Image was made Grayscale under Image>Mode>Grayscale.
A new adjustment layer was added and under Image>Adjustments>Levels, blacks were pushed to 73 and whites were placed at 197.
The image was inverted to a negative under Image>Adjustments>Invert.
The image is ready to print. As mentioned above, we placed different print parameters for the two plates to see if, in addition to the new Photoshop settings, a certain print profile was best suited for the image dot pattern.
Both images adhered to the following settings: under Image Size had the “resample image” box unchecked, resolution set at 300 ppi, and in the Print Preview dialoge box under “Print Profile” Gray Gamma 2 was selected. Color handling set at “Let Photoshop determine colors” and Rendering Intent set at Perceptual.
Plate C: Under “Print Settings” the media type was set at “Plain Paper” and Print Resolution set at 600 dpi.
Plate D: Under “Print Settings” the media type was set at “Plain Paper” and Print Resolution set at 300 dpi.
Both images were ironed with a tacking iron at 300 degrees F for 8 minutes.
Both plates were etched in a 40 degrees Baume Ferric Chloride bath.
Timed Application of Mordant
30 minutes in a vertical tank
Removal of Grounds
Grounds were removed with 00 gauge steel wool.
After Bath Evaluation
Both plates were obviously well-etched, but both images still showed the harsh diagonal lines where it appeared the grays would be most delicate.
Plate was inked with Graphic Chemical Etching Ink in Bone Black, applied with a piece of mat board. It was gently hand-wiped in an outwards motion with a piece of tarletan.
Paper Type: Hahnemuhle Copperplate
Paper Soaking Time: 10 Minutes
Press Blanket Setup: Takach pressure at 5.5, 2 blankets, sheet of newsprint
Both images have a better amount of detail than Test 9, but not more so than previous trials. Etching for 30 minutes may be too strong and perhaps could be eating the diagonals through the image where it is most delicate.