Re: Approval and ICC
Re: Approval and ICC
- Subject: Re: Approval and ICC
- From: Henrik Holmegaard <email@hidden>
- Date: Mon, 13 Nov 2000 08:08:35 +0100
... you're saying that good color or match color is a function of dot
structure, screening, rotation, rosette and density. Interesting I
thought matching color was about matching color. Approval is a great
machine but because of the different colorants used in proofing systems
and printing systems, using an ICC profile is the best tool available
for achieving the holy grail of match color.
That's what I'd call sharpening the conceptual point -:).
The way I see it, the Kodak Polychrome Approval is a nice device, but
it has some drawbacks, too.
The Approval is basically a dye sublimation process, just like the
86XX and 9000 models from Kodak Professional and Kodak Polychrome.
The difference is that a perforated vacuum bed holds the receiver
firmly in place (it travels four times back and forth in the small
subs which rules out proofing of trapping etc), while four foil
panels are pulled across the receiver in turn, and heated with lasers
to create a dye sublimation process. The resolution of the dye
sublimation process is 1800 - 2450 dpi, compared to the 300 dpi of
the smaller subs.
At its simplest, if the idea is to proof on plain paper, it's
logistically not that easy to do. We're talking of a very expensive
device, and naturally a lot of workstations will be printing to it.
If the workstations target different papers, then there's a problem,
because the Approval main unit has no automated paper handling
mechanism. An operator has to pull the receiver with foils out of the
main unit, carry it to the laminator, put the right paper into the
laminator, and complete the proof generation process. Also you can't
put newsprint into the laminator because it doesn't take heat well
(it's unstable and creases).
To profile an Approval device, this is what you have to do, that is,
create a final proof - on a specific paper. Each time you apply the
proof profile, you replicate the workflow (carry the receiver to the
laminator, line up in the queue after Jack and the new guy whose name
you forget, look on the shelf for the production paper, put it into
the laminator, and there you are). Any differences caused by dot
patterns (and the Harlequin RIP was supposed to be able to replicate
production screening) comes second.
When I last tested the Approval, the RIP didn't accept ICC device
profiles. At that time Kodak Polychrome had been working on support
for ICC device profiles for a while. Maybe it's finished now.
As I recall the foils were intended to match SWOP inks, and four
foils were implemented with two to come. The idea was to reserve gold
and silver PMS foils for the two remaining spindles as these colors
can't be simulated in any process systems. This idea might have
changed, too, with a wide gamut solution for all six spindles, in
which case you run into other problems as the ICC world is still a
four channel one. Probably when Kodak worked with Quark on the Quark
CMS and its hi-fi implementation, the idea may have been that this
workflow landscape would change faster than it has.
When you look at the device, it's a very good idea, but it's not
really logistically finished. The paper handling has to be automated,
the RIP has to work, and the six spindle solution either has to have
a PMS to 'ApprovalFoils.ICC' conversion utility for the non-metallics
to be simulated (something along the lines of the GretagMacbeth
ColorPicker, I'd say), or it has to have a solution for six foil wide
gamut proofing.
Kodak Polychrome is also maybe the strongest proponent of device link
profiles, and again device link profiles are OK as such, but in
relation to a proofer like the Approval they just don't make the
workflow any easier, rather much more difficult and complex.
I never got around to checking this out, but third party
implementations for the Approval have been in the press in the past,
including implementations from Scitex and Heidelberg.
--
------------------------------------------
Henrik Holmegaard, TechWrite
Stationay +45 3880 0721 - +45 3881 0721
Mobile +45 2178 3959
Toelloesevej 69, 2700 Broenshoej, Denmark
------------------------------------------
- Follow-Ups:
- Monitor
- From: sander <email@hidden>