RE: How to make a linearization ?
RE: How to make a linearization ?
- Subject: RE: How to make a linearization ?
- From: Ray Maxwell <email@hidden>
- Date: Mon, 25 Aug 2003 10:03:57 -0700
One more point...If you reduce the limits of one ink, reduce the others to
reach proper gray banlance. Some software allows this... others do not.
Ray
Creo
Ray Maxwell | Senior Color Systems Engineer, Inkjet Printing
4225 Kincaid Street | Phone (604) 451-2700 ext. 2004
Burnaby, B.C.
Canada V5G 4P5
IMAGINE CREATE BELIEVE
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From: Ray Maxwell
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Sent: Monday, August 25, 2003 9:45 AM
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To: email@hidden; 'Peter Baumbach'
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Subject: RE: How to make a linearization ?
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Hi Peter,
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The simple answer is to set the limits at a point where the density
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reaches
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a maximum. Many people set ink limits in this way. However, you may
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cause
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your color management software and profile making software to work
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overtime
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to correct some problems you may introduce. As well as looking at
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density,
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I suggest that you plot the a* and b* values for each color step wedge.
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You
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just plot the a* vs. b* from you CIELab measurements. When you do this
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you
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will find that some ink and paper combinations cause the Hue to change and
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the chroma to decrease at the point that the inks reach saturation. You
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should set you ink limits so that you don't go past the maximum chroma
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point. Please note that this is another "rule of thumb". When we chose
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ink
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limits for our systems we measure density and CIELab and then plot input
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tint vs. density, a* vs. b*, and input tint vs. chroma. We look at the
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level that causes mottling or slow drying of the inks. We look at color
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drift when using different ink levels. What I am saying is that there are
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many factors that can be examined before you can set the ink levels to
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what
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may be their optimum values. However, looking at density and CIELab is a
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good place to start. I would also suggest that if you are doing proofing
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of
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offset presswork you use about 20% dot gain when you calibrate you inkjet
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before profiling.
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Hope this helps,
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Ray
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Creo
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Ray Maxwell | Senior Color Systems Engineer, Inkjet Printing
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4225 Kincaid Street | Phone (604) 451-2700 ext. 2004
>
Burnaby, B.C.
>
Canada V5G 4P5
>
IMAGINE CREATE BELIEVE
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