Re: Printing CMYK from Quark vs. Photoshop to color laser
Re: Printing CMYK from Quark vs. Photoshop to color laser
- Subject: Re: Printing CMYK from Quark vs. Photoshop to color laser
- From: Jan-Peter Homann <email@hidden>
- Date: Wed, 30 May 2001 11:30:29 +0200
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From: Wim Melis <email@hidden>
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The purpose of these tests is get both Quark and PS into an identical
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state with straight CMYK, without using any colormanagement. But how can I get
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them to print the same?
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Wim
Hi Wim
If a laser-printer is driven with raw CMYK-data with no kind of color
correction, the print-out is in most cases to dark compared to the offset-print.
If the printing from PhotoShop is visual better, than in QXP, it seems that
there was some kind of printout color-correction.
I know at least five possibilities of such print-out color correction:
1) Transfer-Curves
These are gradation curves which are applied only when the image is printed. You
can specify transfer-curves in the options in the printing dialogue.
2) Color-Sync Colormanagement
The Color-Correction is done by the CMM on the computer. You have to specify a
target-profile in the printing dialogue of Photoshop.
3) Printer-Driver Colormanagement
The Color Correction is done inside the RIP with standard-functions of the RIP.
You specify a source-profile in the normal printing dialogue. The printer-driver
converts this to a PostScript CSA. Inside the RIP the CMYK-Data is converted
with the CSA to Lab and then convertes by an internal CRD to the printer CMYK
4) EPS/PostScript Colormanagement
If save an image as EPS and you click the button "PostScrip Colormanagement" the
icc-profile of your document-space will be embedded in the EPS. If you print
this EPS from any application, it will be definitely colormanaged in the
PostScript-RIP. Even if you disable Colormanagement in the application wich
contains the EPS. Inside the RIP the embedded icc-profile is converted to a CSA,
the following colormanagement is like as in 3)
5) QMS internal Colormanagement
A lot of QMS printer have internal color-corrections. You can activate them in
the printer specific options in the printer driver.
There you have e.g. "SWOP" "Euroscale" "No Colormanagement". In this case the
CMYK-Data will be color corrected by a probietary QMS-engine inside the RIP.
This parts are only about printing CMYK-images....
What about the interaction between the image and the layout application ?
What about making PDF before printing ?
Sometimes, I think all the colormanagement-architects from Adobe, Apple, Quark,
Macromedia, Heidelberg...
must be punished to do colormanagement troubleshooting at the client-side.
--
Jan-Peter Homann
mailto:email@hidden
http://www.colormanagement.de