Photoshop: duotone for printmaking

Preparing photographic positives

To prepare photographic positives for photoscreen and photolithography all digital images or photographs need to be converted to greyscale and printed in black ink only onto transparent film using an inkjet or laser printer. If an image contains greys it is better to darken them as they are likely to overexpose and not show up in the print.

  • Image sizes:Image resolution: 300ppi.
  • Plate sizes: A3 37x45cms allow 6cms border so height 39cms and constrain proportions. A4: 38×25.3cms

Use CMYK? 8bit. Convert to bitmap. Output 700dpi. Method Halftone screen OK. Frequency 47 lines/inch, angle 30 degrees, Shape round.