Re: Profiles for HP950
Re: Profiles for HP950
- Subject: Re: Profiles for HP950
- From: Peter MacLeod <email@hidden>
- Date: Wed, 12 Dec 2001 17:55:45 -0800
At 3:24 PM -0700 12/12/01, Jules wrote:
I'm using Adobe Pressready with my HP952c. I've installed the
colorsync profiles supplied from Adobe but cannot find any
information explaining the profiles i.e.-which profile for which
paper type. I've searched through Adobe and HP's knowledgebases to
no avail.
Does anyone know where the info explaining the profiles can be found?
Here is what I posted to this list about a year ago.
(Usual disclaimers apply :)
Regards,
Peter
---
The naming scheme is:
[Printer Name][Ink System][Mode][Paper].ICM
Where "Printer Name" is a shortcut for the printer, such as "EP1200",
"Ink System" is a single-character code designating whether it's
normal ("N") or photo ("P") ink. This is there because some printers
can have either ink system installed.
"Mode" is a single-character mode selector:
D = Draft
N = Normal
B = Best
The combination of print speed, number of passes, resolution etc. is
determined internally based on the mode selector, and usually matches
what the native driver does.
"Paper" is a two-character paper code, and this will be the hardest to
decipher. I can list some from memory, but Your Mileage May Vary.
PP = Plain Paper
PI = HP Premium Inkjet
PG = HP Photo Glossy
QJ = Epson premium inkjet
GP = Glossy Paper
GF = Glossy Film
HW = HP Heavyweight Inkjet
TR = Transparency
RD = HP Rapid Dry Transparency
For every printer, the profiles provided are only the OEM papers.
Some codes are shared between printers, i.e. if there's a glossy film,
it's always "GF", but then it branches out on OEM-specific substrates.
As for the ".ICM" on the end, don't ask...
If you want to replace a profile with your own, it's best to pick
a substrate that is similar to the one you're trying to use, because
on many inkjet printers, the drying times vary a lot, and you want
to pick an interleave and print speed appropriate for the substrate.
Native drivers are usually doing the ink limiting for you, but in
PressReady the ink limits were built into the profiles, which is
both good and bad--good in that you get direct control over CMYK
colorants, bad in that it's easy to get a horrible result if you
don't have a profiling tool that can limit ink.
Indeed, as someone asked, the "proofing" transform uses perceptual
intent. If you want to get around it, you have two choices.
The first is to use PostScript-based color management.
PressReady does generate CRDs for all of the rendering intents,
and if you use an application that selects rendering
intent in the PostScript stream (i.e. uses findcolorrendering) then
it should work. Unfortunately many applications don't emit
rendering intent selection.
The other is, as you pointed out, to turn the proofing transform
off, and just do color management upstream in your application.
Finally, I should point out that it is possible to figure out the
substrate names from the PPD file, at least in most cases. If you
look at the media type list in the PPD, you'll see lines like this:
*MediaType HPRapidDryTransparency/Rapid-Dry Transparency:
"/EngineMedia 600 AddPressReadyRenderingInfo ResetRenderingInfo"
(This example is from the HP895C PPD).
Note the /EngineMedia 600. If you look further up in the PPD
where the PressReady_Ink_Media dictionary is defined, you can find
the profile for that EngineMedia code. 600 maps to "HP895NxRD.ICM"
in this case, where "x" is the quality, though for that particular
substrate there's only one quality setting, normal, or "N".
The PPD files are in "System Folder:Extensions:Printer Descriptions"
on the Mac. For the given example, the PPD name is "HP 895C (PressReady)"
--Peter