Many thanks Aaron,
I'm using PatchTool and I1Profiler for all this and all pertinent
documentation (AN-3, AN-4), profiles, charts, etc.
I'm using the patch and profile provided with PatchTool or Ideal
Alliance for the Gracol Coated 1 2006.
I have a question though about these IT8.7-4 charts, they seem to be
paper specific. There are about a dozen of them and all have the same
CMYK values but different XYZ and LAB values.
This bring a question, since this data is for this or that paper,
shouldn't we have a similar data set for the specific paper we'll be using?
Though I've verified that the Gracol profile gamut is well inside the
gamut of the paper I'm testing, which mean no risk of clipping.
The tiff file created by I1Profiler as no profile, so I assume I have to
assign the Gracol profile the data is based on. (Photoshop)
Then I should print it using the (dark printing) profile, you say I
should use the absolute rendering intent, right?
After, you say this below, I assume that is for when I want to print
without color management, which is not the case here.
"Either that or just print directly from Photoshop using a null
transform so that you can print without colour management active."
I not really sure about this above, doesn't this convert twice, in
theory it shouldn't do nothing to the colors but in practice, this is
very likely to introduce some "conversion" errors? May be they are not
significant, I don't know.
Since I have I1Profiler, are there any known problems printing target
charts directly? I used that to print my target when it's possible.
I hope this works fine, because if it doesn't, it could be the cause for
my profiles printing to dark, at least potentially.
Regards,
Yves
PS. the Gracol chart is printed according to these recommendation, but
I'm not convinced using the Absolute colorimetric intent is the right
way to go. This paper must have loads of OBAs paper white is visibly
much bluer then the paper I used.
We'll see, the measures maybe almost perfect though.
On 3/28/2022 1:15 AM, Aaron Perelmuter wrote:
I couldn't agree more about the ruler, it works great.
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx
<argyllcms-bounce@xxxxxxxxxxxxx> On
Behalf Of Yves Gauvreau
Sent: Sunday, March 27, 2022 11:27 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: Ideal Alliance proofing certification
guidelines
I'm satisfied with the monitor proofing certification guidelines
but for
printing, since it's all about CYMK, I wonder if any of you have
suggestions
to adapt all of this to an RGB printer.
The Idealliance monitor and printer proofing certification procedures are device agnostic, in that it doesn’t matter if you’re using an RGB or CMYK device because it’s specifically the proofing which is being examined and proofing is done in whatever colourspace the device uses.
In your example (and mine too), you’re using both an RGB monitor and printer. In Photoshop, when you go to print the IT8.7/4 chart, you need to select Absolute Colorimetric in the Colour Handling section of the print dialogue. Simply choose the profile in question, the one you say is making prints which are too dark.
It’s a very straightforward and simple process if you follow the directions as documented on the BabelColor website in their Application Note #3 pdf, which can be found on the Tutorials page on their site.
You need the Gracol/SWOP profile of the standard (printing condition) to which you are proofing/certifying and also a TIFF of the IT8.7/4 target-create the TIFF using i1Profiler. All of these are freely available from a variety of sources. Finally, you’ll also require the reference file for said target, which you can load into i1Profiler so you can measure your target. It doesn’t matter if you select the randomised or visual layout as each patch is numbered and will sort itself out in PatchTool. The reason I suggest using i1Profiler for creation of the target and subsequent measurement is that I’ve found it to have quite robust measurements when using an i1pro2 and the zebra ruler, in that it’s relatively easy to measure the target without too much hassle or having to repeat the measurement of various rows due to having too many errors.
It probably sounds more difficult and time consuming in writing than it really is. Best thing is to download the BabelColor pdf and follow the procedure it describes, and I suggest following Workflow-2, it offers less places to make mistakes, imho.
One last thing, I’d recommend using the Dry Creek Photo target printing application as opposed to Adobe’s similar software as it doesn’t have any issues with reducing the size of the image it’s printing. Either that or just print directly from Photoshop using a null transform so that you can print without colour management active.
Cheers,
Aaron.
I used the "GRACoL2006 Coated1 IT8.7-4.txt (M1)" reference file
for the
monitor do you think I could use it as well for the printer?
Yves
