color check 101

[Dario]

Hi all,
just a general question...
How do you manage your color consistency in your printing environment?
Do you fingerprint every press run setup?
Then you use those icc profiles to color proof?
And then what?
How often do you check your machines?
What do you do to check the colors on the product? Color paches?
What else?
(please be verbose)
Thanks!

 

[Magnus59]

We used to fingerprint each machine and create an ICC Profile using Scitex Profile Wizard, but changed our methodology a few years ago, and now setup the presses to print to ISO standards, Calibrate our plotters to a baseline and proof using a FOGRA 39 profile. It's easier to maintain consistency this way, and if you outsource work to other printers who have also set their printing conditions up to ISO standards, you should also get consistent colours between your own plant and work printed outside.
Colour densities are checked on press with colour bars (in our case, they are Heidelberg specific) and Axis Control.

 

[SteveSuffRIT]

How do you manage your color consistency in your printing environment?
Calibration gets the color accurate, then process control keeps it consistent, repeatable.

Do you fingerprint every press run setup?
Each press is fingerprinted with 3 stocks, gloss, matte, uncoated.
Purpose is to see how close or different they are to each other.
If close, average and use 1 plate curve for each paper type.

Then you use those icc profiles to color proof?
Use a generic not a custom ICC profile. Target ISO 15339 and CRPC

How often do you check your machines?
In theory, each press run is a mini-check. At SID & TVI, press should visually match proof.
Occasionally when paper space allows, print proof verification bar and check that.

What do you do to check the colors on the product?
Spot colors in live work, dE <=3.0
Process color in colorbar, SID +/-0.07, TVI +/-3%, Mid-tone spread <4%, Gray Balance dC

 

[Dario]

Thank you Steve!

Each press is fingerprinted with 3 stocks, gloss, matte, uncoated.
Then you use those icc profiles to color proof?
Use a generic not a custom ICC profile.

How can you work with actual different ICC profiles and then color proofing using a generic one? (just asking)

In theory, each press run is a mini-check. At SID & TVI, press should visually match proof.

Since you said "visual" therefore you don't "measure" anything, I suppose.

Process color in colorbar, SID +/-0.07, TVI +/-3%, Mid-tone spread <4%, Gray Balance dC

What do you mean by "SID" and "dC" ?
(sorry for my bad English)

 

[Dario]

Hi Magnus!

a few years ago, and now setup the presses to print to ISO standards

That's a clever way to work indeed!
...but what if your paper is out of Iso standard?

 

[Magnus59]

Hi Magnus!



That's a clever way to work indeed!
...but what if your paper is out of Iso standard?

In the digital world you can calibrate a device for each paper stock, that's not feasible in the offset world.
We run to the solid ink densities we established when the colour expert commissioned by Kodak came and set up our presses and plate curves

 

[SteveSuffRIT]

How can you work with actual different ICC profiles and then color proofing using a generic one? (just asking)

Generic is for "close enough" dE'00 <= 5 @95%

Since you said "visual" therefore you don't "measure" anything, I suppose.

No, you measure SID & TVI.

What do you mean by "SID" and "dC" ?

SID is Solid Ink Density, TVI is Tone Value Increase, dC is C* Chroma

 

[SteveSuffRIT]

In the digital world you can calibrate a device for each paper stock, that's not feasible in the offset world.
We run to the solid ink densities we established when the colour expert commissioned by Kodak came and set up our presses and plate curves

The calibration is for not each different paper type, that's not necessary.
The calibration is for just 3 broad general groups, gloss coated, (satin,matte,dull), and uncoated

 

[SteveSuffRIT]

In the digital world you can calibrate a device for each paper stock, that's not feasible in the offset world.
We run to the solid ink densities we established when the colour expert commissioned by Kodak came and set up our presses and plate curves

You can use Substrate Corrected Colorimetric Aims (SCCA), which is a mathematical conversion.

 

[Dario]

SCCA

that's nice!

 

[Dario]

Hello guys, sorry to resume this old post, but any of yous maybe know the steps of a SCCA conversion? I'm asking just for academic purposes, since I know nothing about this process, and I own no softwares...
what are the steps?
From what I've found could be:
1) problem: you are printing on a different colored substrate
2) measure the new substrate
3) confront it it's less deltaE 4 than the target
4) use a software (which one?) to remap the chosen icc profile
5) use the new profile
What am I missing? Can some provide more detailed info?
THANKS!!