SWOP TROO1 / PO4
SWOP TROO1 / PO4
- Subject: SWOP TROO1 / PO4
- From: Henrik Holmegaard <email@hidden>
- Date: Wed, 15 Nov 2000 08:24:42 +0100
Chris Murphy <email@hidden> wrote:
>
Others have reported similar good results with the "CS ColorMatch 3.01
>
SWOP Sf C" profile. What I'm looking for is a true SWOP profile - i.e.,
>
one that is based on TR001.
On the Printopen 4 CD you'll find a SWOP ANSI CGATS-TROO1 production profile.
The measurement data set reflects black backing just as the ISO BVD sets do.
Note that the Lab -> CMYK B2A1 table used for proofing is 16 bit in
two of three cases, (a) all are 16 bit if you choose large size, (b)
all but B2A1 are 8 bit if you choose medium size, (c) all are 8 bit
if you choose small size. The SWOP TR001 profile is medium size, and
the proofing table is 16 bit. As in past autoconfiguration concepts
the idea is to secure the fidelity of the proof print.
Another difference between PO3X and PO4 for proofing is that there
are now more ways to affect the white point. As before, software
switches let you autofix optical brightener (: fluorescence) and too
low L in the proof paper. But now when the profile is calculated, you
can also modify the white point. The new command lets you control
both L *a and *b, that is, lightness and tint. The lightness
adaptation for proof switch still only affects the L channel of the
proof (and just the lighter tones), the fluorescence option still
only neutralizes minus *b in the paper (both proof and print), but
the new control has a slightly different use in helping to nail the
paper simulation. Because there is always interpolation with ICC
profiles, in some combinations of production and proof profile you'll
be right on and in others a little off in the paper simulation. When
you're a little off, and the proof is important to you, this control
lets you tweak the white point a tiny bit in order to get it right.
From the bundled profile ReadMe:
ReadMe CGATS-TR001 Profile, Version 07/2000
ICC profile for SWOP offset printing
* SWOP_CGATS-TR1 U300 K95 PO4.icc
The profile calculations are based on characterization data published
by ANSI/CGATS in the technical report "ANSI/CGATS TR001-1995" [1].
* Profile Generation
The profiles were generated with Printopen 4.0 and with the standard
settings. For black generation a degree of undercolor removal was
used that produces a maximum tone value sum of 300%. The maximum tone
value for the process color black is 95%.
* Notes on characterization data
The profiles are based on characterization tables that were generated
using the standard procedure for outputting a digital data set
specified in ANSI/IT8.7/3-1993 [3]. Printing of the color table was
performed on a sheet-fed press under carefully controlled printing
conditions of ANSI/CGATS.6-1995 [2] resp. SWOP [5] . Colorimetric
measurement with a spectrophotometer followed the standard for
graphic arts, namely ANSI/CGATS.5-1995 [4] , which specifies geometry
0/45 or 45/0, 2 degree observer, illuminant D50 and a black backing
behind the sample. For further details on the characterization data
see the technical report "ANSI/CGATS TR001-1995" [1].
* References
[1] ANSI/CGATS TR001-1995 Graphic technology -Color Characterization
Data for Type 1 Printing.
[2] ANSI/CGATS.6-1995 Graphic technology - Specifications for
graphics arts printing - Type1.
[3] ANSI/IT8.7/3-1993 Graphic technology - Input data for
characterization of 4-color process printing.
[4] ANSI/CGATS.5-1995 Graphic technology - Spectral measurement and
colorimetric computation for graphis arts images.
[5] SWOP, Specification Web Offset Publications,1993; SWOP
Incorporated, 60 East 42nd Street, Suite 721, New York, NY, 10165.