Re: BEST/Epson and Black Generation (Darrin Southern)
Re: BEST/Epson and Black Generation (Darrin Southern)
- Subject: Re: BEST/Epson and Black Generation (Darrin Southern)
- From: Jan-Peter Homann <email@hidden>
- Date: Mon, 12 Feb 2001 19:49:36 +0100
email@hidden wrote:
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Message: 1
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Date: Mon, 12 Feb 2001 17:58:00 +1100
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Subject: Epson Printers and Black Generation
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From: Darrin Southern <email@hidden>
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To: "colorsync users lists.apple.com" <email@hidden>
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Dear List,
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I have been working on an issue regarding the CYMK printing to the Epson
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7000, 7500, 9000 + 9500 printers and the role the black generation places
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with profiles built and applied to the BEST Color Rip.
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I have put a scan of a baseline test printed from the BEST to the Epson 7000
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on my homepage at http://homepage.mac.com/darrinsouthern/ the two files are
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80k and 140k, (this was the smallest without loosing quality).
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This test was printed without any 'paper' or 'reference' profiles. It was
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printed with the BEST rip set to 720 dpi (1440 dpi gave the same sort of
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result)
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The Epson 7000 has the light magenta and light cyan to build the lighter
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colors, and the yellow ink does not show up the dot pattern (stiple).
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The Epson 9500 prints the baseline target the same way.
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The problem is the black, which seems to print a very large dot for the
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lighter shades. This becomes an issue when lighter colors are needed to be
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proofed, and this output I have mentioned before on the digest as the 'dodgy
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black stiple'.
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I have then built a paper profile without a reference profile, and then
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printed any test file with the 'BESTref5' profile as the reference profile.
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I printed the 'QualityofColors' file and set the total ink to 180%.
As I understand the BEST-Software, the reducing of total ink to 180% is doing a
internal GCR in the RIP.
In the internal Dataflow of the RIP, this GCR is applied after the
colortransformation by the profiles.
Even if your profile for the proofing media is build without black, the internal
GCR will cause the black dots in your print,
Try to print the testchart with the highest amount of total ink, even if the dark
colors in the testchart have no stabil borders. Choose now the total amount of Ink
low as necessary in the profiling software with a very short black for the profile
of your media.
:-) Jan-Peter
--
Jan-Peter Homann
mailto:email@hidden
http://www.colormanagement.de