Creating new Media Configuration and paper profile

[rwolfe1970]

I'm trying to create a GRACoL 2006 Coated 1v2 compliant proof with an Epson 9880 printer being driven by Kodak Proofing Software v4.2.1.

We switched papers recently and I'm trying to creating a new media configuration with the KPS and a paper profile with Profile Maker 5. After going through both processes, I viewed the gamut of my new paper profile and the GRACoL profile together in Profile Maker. The problem I'm seeing is that the paper profile gamut doesn't encompass all of the GRACoL gamut.

Can I edit the paper profile to fix this or do I need to redo the Media Configuration first and then redo the paper profile? I've already done this process twice without much change from one time to the next.

The paper is Alameda FXAV Satin and is listed as being GRACoL compliant.

 

[Stephen Marsh]

The gamut of the device profile will mostly be governed by the total ink limit set in the media configuration. You wish to lay down almost as much ink as you can, however you don’t also wish to create drying issues, ink mottling, pooling, fill in of fine reverses and other ink laydown artefacts/errors in dark saturated colour combinations – it is a balancing act. You need enough ink to have a good gamut, but not too much ink.

What device resolution is the media configuration? 720x720, 720x1440 etc.

What total ink limit was set in the KPS Media Configuration wizard?

Generally the issue is that the reference printing condition will generally be in gamut for the proofer in almost all areas – except for very deep shadows.

The attached ColorSync gamut plots (3D viewed from direct top and bottom) are from an x890 model using and Satin paper and GRACoL06.





Stephen Marsh

 

[rwolfe1970]

Stephen, thanks for the insights!

Device Resolution is 720 x 720
Total Ink Limit in KPS Media Configuration was set at 1.6 (I believe 4.0 is the highest setting)

I have a feeling I set the Total Ink Limit too low. I started to see streaking in one of the color patches with the TIL higher than 1.7 though. I'll redo the process again with a higher limit and see if that helps.
When a P2P target was read, we were told "it passes the IDEAlliance metrics for tonality, gray balance and the GRACoL color aims. But the Yellow TVI curve is lacking in the highlights, gray balance could be better and the green is close to the tolerance fail point."

Hopefully some of those issues will be resolved if I can produce a larger gamut with higher Ink Limits.

 

[Stephen Marsh]

Stephen, thanks for the insights!

Device Resolution is 720 x 720
Total Ink Limit in KPS Media Configuration was set at 1.6 (I believe 4.0 is the highest setting)

I have a feeling I set the Total Ink Limit too low. I started to see streaking in one of the color patches with the TIL higher than 1.7 though. I'll redo the process again with a higher limit and see if that helps.
When a P2P target was read, we were told "it passes the IDEAlliance metrics for tonality, gray balance and the GRACoL color aims. But the Yellow TVI curve is lacking in the highlights, gray balance could be better and the green is close to the tolerance fail point."

Hopefully some of those issues will be resolved if I can produce a larger gamut with higher Ink Limits.

Based on your feedback, I’m not sure if this is *lack of* total ink limit. As you say, artefacts appeared with 1.7 or higher.

It may be too much ink! I have heard that one can get a gamut decrease if too much ink is applied (there is a turning point), however I have never encountered this myself. As I said, I try to lay down enough ink to get the job done without using too much ink, so I have not pushed the envelope.

When I make media configs for a good proofing media, say 180-260gsm semi matte/satin, the ink limit is generally 1.2 (whether or not the model is x800, x880, x890 or x900). For a lightweight imposition/content or photo plan matte coated media around 100gsm, the total ink limit is generally around 0.7. These numbers are of course device and media dependent.

[FONT=arial, sans-serif]KPS does not have an automated iterative colour matching engine as found with high end proofing software, it simply uses either standard device ICC or devicelink profiles (you get what you pay for). The best that one can do to tweak things is to make edits using a devicelink profile editor such as Kodak ColorFlow for KPS Matchprint Inkjet.[/FONT]

[FONT=arial, sans-serif]You will probably get a Fogra or IDEAlliance colour bar/media wedge to pass certification on every patch, however there may still be other areas of the proof that are out of gamut. Whether or not this can be noticed by the human observer is another debate, however a spectro will probably see minor differences between proof and press sheet. Remember that “specification based printing” is allowing a dE76 value of +/- 6 for non critical colours, so there is a lot of leeway for variation. The press will likely be way more variable than the proof.[/FONT]


[FONT=arial, sans-serif]Stephen Marsh[/FONT]