Raster-based files can be prone to artifacts on the final output without proper page preparation. (An artifact is an unexpected element, usually a single-pixel black or white line.) High-resolution loose page proofs may not show artifacts, although a high-resolution imposition proof often does. Here are some recommendations for reducing artifacts.
Ensure that LW and output resolution match when imaging
Before submitting pages for final output, make sure that the LW resolution matches the final output device resolution. If the LW resolution doesn't match the output device resolution, Prinergy must resample the LW data at the output stage, which may introduce artifacts.
You can set the LW output resolution on a Brisque when creating CT/LW pages. For example, if you are outputting to a 2400 dpi Kodak Trendsetter platesetter, RIP your pages to CT/LW with the LW resolution set at 2400.0 dpi (94.48819 dpm). Or, you can set the LW by refining the CT/LW file with a refine process template with the CEPSConversion JTP enabled and set to resample at the appropriate LW resolution. Use the Prinergy Process Template Editor to create or edit a refine process template.
RIPing to the device resolution has no visible impact on final output and is recommended for use with all CT/LW files. Setting the LW resolution on a Brisque, that is, creating CT/LW at the correct resolution, is preferable to setting it in Prinergy where you resample to correct resolution at the conversion stage. Resampling to at the conversion stage may have a slight visible impact, since resampling errors may occur.
Avoid running Copydot pages through the Brisque
A copydot page that was run through the Brisque is susceptible to moiré artifacts unless extreme care is taken.
Using the CEPS JTP
LW resolution: If possible, RIP LW to 2400 dpi (94.48819 dpm). Always resample at the CEPS JTP stage of your refine process template to ensure the resolution is correct.
Using PDF2Go on Brisque version 3
CT resolution: Should be set to a dpi that converts easily into PostScript points. Recommended settings in dpi are: 300 dpi (11.81102 dpm), 320, 360, 375, 400, 450, 480, 500, 576, 600, 720, 750, and 800. This option may have a very slight negative impact on your final output quality, due to lowered CT resolution. If possible, RIP CT to 300 dpi. Always resample at the PDF2Go stage as well, to ensure that the resolution is correct.
LW resolution: If possible, RIP LW to 2400 dpi (94.48819 dpm). Always resample at the PDF2Go stage to ensure that the resolution is correct.
Using PDF2Go on Brisque version 4
LW resolution: If possible, RIP LW to 2400 dpi (94.48819 dpm). Always resample at the PDF2Go stage to ensure that the resolution is correct.
Using ExportPS – Any Version
ExportPS is not currently recommended for bringing pages into Prinergy. However, if using ExportPS, extreme caution must be taken at the RIP stage, that is, at CT/LW creation, to ensure that the LW resolution matches the intended device resolution, for example, 2400 dpi (94.48819 dpm). This is because ExportPS does not resample the page. Sending an ExportPS page with the wrong resolution for output in Prinergy, that is, resampling at the output stage, can introduce artifacts.
Using the PostScript Bypass feature will enable you to avoid artifacts on final output when importing ExportPS DCS files into Prinergy. Contact your Kodak representative to set this up.