GRACoL as opposed to SWOP colour spaces

[Donateli]

Hi I have a question concerning colour spaces, GRACoL as opposed to SWOP in particular. I need to establish a uniform colour space for our prepress department to work in so that our prepress operators will be consistent. Presently the default colour space is SWOP.
We have recently changed our press curves to run as GRACoL and the press room has been certified by Idea Alliance. Our Epson proofer is also running to GRACoL specs too. I was wondering if there is any advantage in switching over the working space in Adobe CS (Illustratrator, Photoshop and InDesign) to GRACoL exclusively?
I see a down side to this as far as legacy work, and there being a colour shift when using some functions in Adobe CS since most peoples working space is SWOP. Is there any real advantage in switching the default colour space from SWOP to GRACoL, especial since most of the files we work on's origanal colour space is SWOP
I have been thinking about this for a while and have come up with no good solutions, has anyone had to deal with this before and established good working method, if you have please share it !
Thanks

 

[David Milisock]

>We have recently changed our press curves to run as GRACoL and the press room has been certified by Idea Alliance.

The cause of any issues and the answer lie in the above statement. All changing the applications to a GRACOL profile would do (assuming identical or very similar TIC values) is to change the gray balance curves so the point is really moot, either way you've introduced a color shift so any issues with color going forward are self inflicted wounds.

I assume you changed to GRACOL to solve color problems. If the change didn't immediately cause an improvement I suggest you go back to what you were doing. If the improvement was evident then stick with the SWOP on the apps and GRACOL elsewhere.

 

[rich apollo]

What kind of stock are you printing on? Therein lies your answer. The GRACoL colorspace describes sheetfed printing on #1 or #2 gloss coated stock. There are two current SWOP colorspaces. One describes web printing on #3 gloss coated stock and the other describes web printing on #5 gloss coated stock.

The advantage to moving your apps to GRACoL is that it is a larger colorspace. I think you'll also find it helpful to get design, proofing, and press all "on the same page".

 

[David Milisock]

>since most peoples working space is SWOP.

How can what you said be true if most of his client files are SWOP? He's just introduced an unnecessary conversion and you can't get more color than they send you. I mewan the man said most people are using SWOP as is the Adobe default.

 

[tmiller_iluvprinting]

It makes absolutely NO SENSE to target GRACol in your pressroom and on your proofer, and then work in a different colorspace in Photoshop. The SWOP files you receive will print fine in GRACol.
Best regards,
Todd

 

[Stephen Marsh]

Hi I have a question concerning colour spaces, GRACoL as opposed to SWOP in particular. I need to establish a uniform colour space for our prepress department to work in so that our prepress operators will be consistent. Presently the default colour space is SWOP.

Do you originate work (internal art studio) - or is it all supplied to you by an outside source? Are supplied files marked with an ICC profile (what profile)? What are total ink weights for supplied CMYK work? These questions are to try to better understand your unique situation.

We have recently changed our press curves to run as GRACoL and the press room has been certified by Idea Alliance. Our Epson proofer is also running to GRACoL specs too.

So your target is now GRACoL, not SWOP.

As mentioned by Todd, SWOP separated files in GRACoL may not be too much of an issue. The seps may be slightly lighter due to more dot gain being factored in. What about gray balance? Hue shifts etc?

I was wondering if there is any advantage in switching over the working space in Adobe CS (Illustratrator, Photoshop and InDesign) to GRACoL exclusively?

Yes, I believe so. Even if you leave things at SWOP, you should setup a GRACoL softproof that preserves colour numbers in existing (SWOP) CMYK data.

I see a down side to this as far as legacy work, and there being a colour shift when using some functions in Adobe CS since most peoples working space is SWOP. Is there any real advantage in switching the default colour space from SWOP to GRACoL, especial since most of the files we work on's origanal colour space is SWOP

Two advantages would be for colour conversions (perhaps not a big issue) and for previews when not using softproofing.

Why leave your internal colour settings at SWOP when you now proof and print to GRACoL? It is all about your Adobe Colour Management Policies in your Colour Settings. You don't have to convert legacy or supplied SWOP files to GRACoL. You simply preserve the colour numbers of the SWOP file and see how it looks when printed in GRACoL. You then have three options: (1) leave things as they are (2) perform edits to the SWOP data to make it look better in GRACoL or (3) convert from SWOP to GRACoL - which is best done using a specially configured DeviceLink profile in your Workflow/RIP.

I have been thinking about this for a while and have come up with no good solutions, has anyone had to deal with this before and established good working method, if you have please share it !
Thanks

This is not a new situation, it was happening long before print standards.


Hope this helps,

Stephen Marsh

 

[Lukas Engqvist]

I'm in europe… so please excuse me if I'm totally wrong… but as I understand it SWOP is a target and GRACoL is a method. Or to express it differently SWOP is a goal and GRACoL is a route to a goal. Is this totally wrong?

 

[meddington]

Gracol and SWOP are both specifications (goals). G7 is a methodology (route to the goal).
However, used in the context of the OP, gracol and swop are referring to ICC profiles...i.e CMYK working spaces that were created from characterization data based on pressruns according to Gracol and SWOP.

 

[Stephen Marsh]

I'm in europe… so please excuse me if I'm totally wrong… but as I understand it SWOP is a target and GRACoL is a method. Or to express it differently SWOP is a goal and GRACoL is a route to a goal. Is this totally wrong?

Lukas, if it helps to think in Euro terms, one could say that SWOP is "similar" to F28 and GRACoL is "similar" to F39 (however SWOP is targeting a different inkset, so there is more of a discrepency than with the Fogra spaces which are more similar to each other).


Stephen Marsh

 

[meddington]

Lukas, if it helps to think in Euro terms, one could say that SWOP is "similar" to F28 and GRACoL is "similar" to F39 (however SWOP is targeting a different inkset, so there is more of a discrepency than with the Fogra spaces which are more similar to each other).
Stephen Marsh

SWOP, Gracol and Fogra should all be using ISO2846 compliant inksets, but perhaps with different acheivable solid CIELab values due to differences in substrate. Gracol and Fogra 39 are actually based off of the same characterization data, with tweaks to gracol for tonality and grey balance.

 

[Stephen Marsh]

SWOP, Gracol and Fogra should all be using ISO2846 compliant inksets, but perhaps with different acheivable solid CIELab values due to differences in substrate. Gracol and Fogra 39 are actually based off of the same characterization data, with tweaks to gracol for tonality and grey balance.

Thanks for the clarification, perhaps the media and solid ink density is what accounts for the differences in the L*a*b* values.


Stephen Marsh

 

[rich apollo]

Lukas, if it helps to think in Euro terms, one could say that SWOP is "similar" to F28 and GRACoL is "similar" to F39 (however SWOP is targeting a different inkset, so there is more of a discrepency than with the Fogra spaces which are more similar to each other).

Stephen,
Why do you say "…SWOP is targeting a different inkset…"?

 

[Stephen Marsh]

Stephen,
Why do you say "…SWOP is targeting a different inkset…"?

When I have compared the solid L*a*b* values of the three most common SWOP profiles to each other, GRACoL and Fogra spaces - the differences made me think that the issue was inksets rather than web vs. flatsheet and stock and solid ink density.

Stephen Marsh

 

[danremaley]

>since most peoples working space is SWOP.

How can what you said be true if most of his client files are SWOP? He's just introduced an unnecessary conversion and you can't get more color than they send you. I mewan the man said most people are using SWOP as is the Adobe default.

For more than 50 years color seps. were made to SWOP standards, (litho had no standards) so the publication industry attempted to get the web printers to proof and print to a standard. Photoshop's default is at, or near, this same 20% midtone gain. In my opinion the best numbers to print to are (DRY) 1.00Y 1.30C 1.40M 1.70 K. With midtone gains of 18%Y 20%M 20%C 22%K. Gracol calls for higher densities but that will cause a Mag. cast at these gain numbers. I teach the pressroom to print the Mag/cyan gains the same and Yelo 2% less - makes perfect gray balance. Lighter or darker depending on the numbers, but most important gray, with ISO inks.
Dan Remaley