Re: Relative vs Absolute in BestColor
Re: Relative vs Absolute in BestColor
- Subject: Re: Relative vs Absolute in BestColor
- From: "Bruce J. Lindbloom" <email@hidden>
- Date: Wed, 22 Aug 2001 09:28:45 -0500
Scott Griswold wrote:
>
Can anyone help explain why I am getting Cyan ink in my whites when printing
>
using Relative Colorimetric? I expected to get paper white, but still get a
>
small amount of Cyan ink in the whites.
One situation that can cause this is if the number of samples in the 3D LUTs
inside the ICC profile is an even number. In this case, pure white (i.e.
Lab = 100, 0, 0) does not have a sample in the table, so the device
equivalent is interpolated from neighboring samples. This interpolation can
lead to a white that is not clean. Different CMMs can also produce somewhat
different results since each uses different interpolation methods.
You can easily determine if your printer profile has an even number of
samples by opening it with Apple's ColorSync Profile Inspector, double click
on the B2A1 tag (which is PCS-to-device, relative colorimetric) and reading
the line in the window that says "X grid points in each CLUT dimension". If
'X' is even, then that is probably the cause of your dirty whites. If that
is the case, then complain to the vendor of the software that made the
profile.
--
Bruce J. Lindbloom, Pictographics Intl. Corp.