Product

Platform

Operating system

Error

Symptoms

Most RIPs can apply calibration to contone data, but not Copydot (or, pre-screened) data. Copydot Toolkit can calibrate Copydot files and 1-bit TIFFs, but what steps are needed, and in what order, to make sure that all the page elements are correctly calibrated?

Cause

Solution

For most prepress systems, the PostScript file of a page containing contone (8- bit) and Copydot (1-bit) data should be RIPed to TIFF, and the resulting TIFF file calibrated in Copydot Toolkit. The contone data should be calibrated by the RIP to match the existing calibration of the Copydot data, not the final target device. (Note that Copydot data is usually calibrated for plate output: often “linear�, that is, no calibration.)

Example: A page containing a Copydot image and a contone image needs to be calibrated for a Spectrum proofer. The Copydot image has been calibrated for plate output.

Step 1: RIP the page to a TIFF, using plate calibration. At this point, the Copydot image has not changed, but the contone image now matches the Copydot image.

Step 2: Calibrate the resulting TIFF file in Copydot Toolkit, using Spectrum calibration. Both the Copydot image and the contone image are calibrated for Spectrum output.

Note: This two-stage process is unnecessary with Prinergy 2.0, which can distinguish Copydot from other digital content and apply calibration to the Copydot only, before RIPing. In the process plan, calibration for Copydot and other digital content is specified, and both calibration curves are applied in turn (first the Copydot calibration, which ignores the other digital content, then the RIP calibration, which ignores the Copydot content).

Permanent fix:

See also

Keywords

calibration, Copydot

Technical contact(s)

Kent Brothers

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Date submitted