Colour Management - Flexo Corrugated

[pcourterelle2]

Hi all,
Does anyone have a good reference for doing colour management on corrugated board using a flexo press?
I specifically interested in what colour profiles could used for both white and kraft board.
White point of the white board is L92.6, a 0.4 b-.013 so bright and neutral but essentially uncoated.
Using a 4-colour ApStar HG2 1632 press

Cheers

 

[emreimanc]

Hi all,
Does anyone have a good reference for doing colour management on corrugated board using a flexo press?
I specifically interested in what colour profiles could used for both white and kraft board.
White point of the white board is L92.6, a 0.4 b-.013 so bright and neutral but essentially uncoated.
Using a 4-colour ApStar HG2 1632 press

Cheers

Hi pcourterelle2,
Are you talking about a proof profile or a dot gain curve?
In both cases it is not recommended to use a standard profile.
There are many variables in printing (mounting tape, flexo plate, inks, etc.).
All these affect the pressure and therefore the profile. You should print a finger print and make a compensation curve. Then you can prepare a proof profile by printing from the plates you buy with this curve.

 

[pcourterelle2]

emreimanc,
Thanks for the reply.
I have a two fingerprint tests scheduled. The first is a single colour test to set a baseline dot gain, and a second using a P2P51 target to gauge CMYK, overprints, and G7. I also have CMYK ink drawdowns our selected flexo inks coming from the ink supplier on our stock. Creating a proper dot gain curve is for the press is not an issue.
The question is what colour profile to use to when converting spot colours to process colour (CMYK)? What is the max TID that can be supported? From what you mention, I have to create my own icc profile. Certainly doable but I was hoping the flexo corrugated world had it's own preferred standards.

 

[realaqu]

Hi all,
Does anyone have a good reference for doing colour management on corrugated board using a flexo press?
I specifically interested in what colour profiles could used for both white and kraft board.
White point of the white board is L92.6, a 0.4 b-.013 so bright and neutral but essentially uncoated.
Using a 4-colour ApStar HG2 1632 press

Cheers

I remebered there is an article on techkonusa website by Ron Ellis about this topic, for non standard white, you might wanna try chromix curve+, just modify white point to make a new profile

G7 Guide for Flexo | Techkon USA

techkonusa.com

 

[pcourterelle2]

realaqu
Thanks for the reply. I've downloaded a copy of the appendix.
We have both Curves4 and Esko ColorPilot.
Cheers

 

[emreimanc]

Hello again.
For spot color conversions;
Esko Equinox or GMG Color Server must be used.
But if you are not printing with ECG, you will not be able to get effective results from spot color conversion. CMYK color gamut will not meet spot color simulation.
Thanks for sharing Realaqu.

 

[pcourterelle2]

We use Esko Equinox and print ECG for offset. The ApStar press is four colour only. It's incorrect to say that the CMYK color gamut will not meet colour simulation for spot colours.
some Pantone colours are easily reproducible using CMYK process inks, just not all PMS colours. Again, my question is in regards to 4-colour printing on corrugated using a flexo press.

 

[SteveSuffRIT]

Previous:
"It's incorrect to say that the CMYK color gamut will not meet colour simulation for spot colours.
some Pantone colours are easily reproducible using CMYK process inks, just not all PMS colours."

It depends on your definition of "close-enough" or "good-enough" color match!
For a DE'00<2.0, CMYK only matches about ~55% of Pantone.
The biggest issue is usually in the C* value, too dirty, not clean enough.

 

[pcourterelle2]

Steve, thanks for the input, but I'm not sure how your point is different than mine. At no point did I say "close enough" or "good enough" so please do not misquote.

Clearly, since the OP refers to printing on corrugated board using a flexo press, colour accuracy will not meet a dE 2 target in the majority of cases, but then no one is expecting that level of accuracy either if we convert Pantone to CMYK for corrugated printing.

My question is does there exist an industry standard profile or characterization set for printing on corrugated board using flexo presses and inks?

We recently tested more than 850 Pantone colours converted to both CMYK and ECG profiles on two different coated stocks using an offset press. As expected, a high percentage of colours with <= 2 dE'00 against the PMS target (not adjusted for print condition) when printed as CMYK. A lot of colours didn't pass, but that was expected. So is it doable? Certainly. Does it work for every Pantone colour? No, but that's what I said.