press n peel test 24

press n peel test 24

Date: October 8, 2013

Room Temperature: 66 degrees Farenheit, dry

Researcher’s Name: Cathe Janke and Kristin Fitzpatrick

Test Summary:
The purpose of this test was to see if changing the image format and filter settings would change the image fidelity and give us a greater tonal range.

Plate Material: .032 Copper 
Plate Size: 4.5″ x 6”

Image Preparation
In Photoshop with the image file open, we made the following adjustments
1. Image>size> 250 dpi
2. Layer> New Adjust Layer> Invert
3. Layer> New Adjust Layer> Color Balance Highlights- Cyan= -31 Magenta= 0 Yellow= -26.
4. Layer> New Adjust Layer> Curves
Curves: Black=45 White=225. Two middle points: Output 62/Input 64 (the gray-black) and Output 171/Input 175 (the gray-white). Or A: O: 45 I: 0  B: 0:62 I: 64      C: 0:171 I: 175     D: 0: 225  I:255
5. Select background layer then Layer> Duplicate layer> background copy selectedClick opacity (by layers) select 75% *turn background (original) OFF, before printing (press eye
button)
6. Flatten Image (under image)
7. Image> grayscale
8. Bitmap (under image)
-select “Diffusion Dither”
For test 4.1 changed resolution output to : 2.500 pixels per         inch
For test 4.2 changed resolution output to: 1,250 pixels per inch.

View of the image in Photoshop 2500 bit

test4_1_2500bit

View of the image in Photoshop 1250 bit test4_2_1250bit_10_8

When printing”printer profile” option not available (this is because of bitmap)

Print Parameters Used
Let Photoshop determine colors
Gray Gamma 2.2
Rendering intent=Perceptual
Presets= Plain Paper
Resolution HQ 1200

The image was printed on the PCB film with a Brother HL2280DW laser printer.

test4bfilm.

Plate Preparation
: We used two for this trial. The plates were beveled, polished with 00 grade steel wool, and degreased with soy sauce and bon ami.

The copper plate was placed on a phone book and the film was placed on its surface print-side-down. The film was carefully heated to the plate with a tacking iron for 8 minutes at 300 degrees F.

Testers found that backing the plate with contact paper was most pragmatic AFTER the plate had been ironed and cooled and with the film still adhered to the plate

test4cironedonfilm test4dbeforeetch

 

Etching Notes: 
The plate was etched in a 39 degrees Baume Ferric Chloride bath in a vertical tank.

Time in Bath  30 minutes

Removal of Grounds
: Plates were saturated with SoySolvII cleaner and left to soak for 5 minutes. Ground was then wiped off easily with a rag.

test4eafteretch

After Bath Evaluation: open bite on 1250 and open bite on 2500 almost all black areas open bit

Inking Methods
: Plate was inked with Graphic Chemical Etching Ink in Bone Black, applied with a piece of mat board. It was gently wiped in an outwards motion with a piece of tarlatan. Then paper wiped.

Paper Type: Hahnemuhle, white
Paper Soaking Time: 30 Minutes
Press Blanket Setup: Takach pressure at 5.5,  2 blankets, sheet of newsprint

t4fproff10_8

Test Conclusion:
Bit map/dither was not effective and the next test will try a photocopy of a tonal drawing to see if issues exist in Photoshop or with PCB film.

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