press n peel test 40

Date: March 6, 2014

Room Temperature: 68 degrees Fahrenheit, dry

Researcher’s Name: Cathe Janke

Test Summary
Objective: Can every image be treated with the same Levels in Curves in Photoshop or does each image require individualized adjustments?

Image was prepared in Photoshop:

Opened and changed to TIFF file
Image>new adjustment layer> Invert
Img>new adj layer>Channel Mixer. Selected “monochrome” option
Img>new adj layer> Curves. 3 points on the curve:
Input 20/Output 0
Input 129/Output 127
Input 219/ Output 171
Input 253/Output 200

Printer settings:
HQ1200
Gray Gamma 2.2
Print option–shape: round
Lpi = 80

Plate A, dpi 544
Plate B, dpi 300

Plate Material: .032 Copper

Plate Size: 4″ x 6.5”

Plate Preparation
:
The plates were beveled, polished with 00 grade steel wool, and degreased with soy sauce and bon ami.

The image was printed on the PCB film with a Brother HL2280DW  laser printer. 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.
test20A3_6platebeforeetch

test20Afilmafteriron

Etching Notes
: The plate was etched in a 42 degrees Baume Ferric Chloride bath in a vertical tank.

Time in Bath:  20 minutes

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

After Bath Evaluation: looks good.

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,  then hand-wiped.

Paper Type: Hahnemuhle, warm white 
Paper Soaking Time: 20 minutes
Press Blanket Setup: Takach pressure at 5.5,  2 blankets, sheet of newsprint

Test Conclusions
The settings in Curves or Levels should be tested for each image, a set number does not seem to work for every image.
The dpi might need to be 72.

test20Aproof Plate A, proof

test20Bproof Plate B, proof

 press n peel test 41 >