press n peel test 39

Date: February, 2014

Room temp: 71 humdity:dry

Researcher’s Name: Liz Bannish

Objective: Is an lpi higher than 80 lpi better for image retention? Also, a new set of curves values was tested at the same time to see how new values react with each lpi.

Plate Material: Copper 0.032

Plate size: 4.5X6″

Plate Preparation: polished with 00 grade steel wool, beveled and degreased with dish soap and soy sauce.

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:
Gray Gamma 2.2
Print option–shape: round

Plate A: All of the above settings except the lpi (lines per inch) was kept constant at 80 lpi
Plate B: All of the above settings except the lpi was changed to 110 lpi

Time in bath: 35 min. Etching bath notes: both plates etched fine,
Ground removal: SoySolvII
Paper: Hanhemule copperplate, soaked 10 minutes
Press: Takach, 2 thin blankets

test19AfilmPlate A, film after ironing

test19BfilmPlate B, film after ironing


test19Aproof Plate A, proof

test19Bproof Plate B, proof

The 80 lpi image had better detail and value retention than plate B with 110 lpi; in the case of plate B the dots placed by the printer were too close together and ferric couldn’t bite through; thus leading to loss of detail. Continuing printing at 80 lpi or perhaps a little higher; but no more than 90 lpi is recommended.

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