Printing with a stochastic screen

[Gregg]

If you are printing with a stochastic screen is there anything you need to do to the files that are different than if you were printing using a conventional halftone screen?

What I mean is, should the resolution be different than your standard 2x the lpi?

Anything else to look out for, or is it just all handled in the platemaking process?

Thanks in advance.
Gregg

[gordo]

RE: If you are printing with a stochastic screen is there anything you need to do to the files that are different than if you were printing using a conventional halftone screen?

What I mean is, should the resolution be different than your standard 2x the lpi?

Anything else to look out for, or is it just all handled in the platemaking process?
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Assuming a 20 micron screen (typical sheetfed) 300 dpi is OK, 400 dpi is better. The lower image resolution may show "staircasing/pixelation"
Scans/images should be very clean - free of scratches, dust, artifacts since the higher resolution of the screen will reveal any defects in the image when it is printed.
A 20 micron screen has a slightly larger gamut than a 175/200 lpi AM/XM screen. As a result, single and two color screen tint builds may be slightly more vibrant (more chroma) than what you are used to.
Other than that there are no special image issues prepress or art prepwise.
Assuming you are not the printer but are sending the job out to be printed - make sure that the printer is using stochastic for the majority of their work rather than just once in a while. I.e. they are experienced with high resolution screening.

best, gordo

[pmkprog]

When I was working with the stocastic screening we didn't do anything different than when we were preparing job for standard screens.
The only thing is that we had a different proofing profile for FM vs AM. Matching flat tint builds is harder to do with the FM, usually the images look just fine.

[alang66]

Your dot gain will be different and you will need to allow for this at platemaking stage if you have any adjustment controls at that stage. Although stochastic screening is considered more stable at different ink weights with regard to dot gain, it is usually a slightly higher dot gain.

[Gregg]

Good stuff, thanks.