Profile To What?

[Tommyjt]

In the past I worked for a litho print shop that later, added grand format printers. In order to achieve a good color match between the two, GRACoL was the source profile used in the RIP.
If I am going to color manage grand format printers for a shop that doesn't have any litho presses, what should be the source profile?
Should I limit the color gamut to GRACoL or use a wider color gamut?
I'm very interested in what is typical for grand format printers.
Thanks!

 

[rich apollo]

You may not want, even, to limit yourself with CMYK. You would be free to adopt an RGB workflow, if you chose. But, it really depends on the incoming files. You are limited to whatever the incoming files are tagged with/built in.

 

[Tommyjt]

Thanks Rich.

 

[Tommyjt]

Any other suggestions?

Thanks

 

[Stephen Marsh]

It may depend on the software, however a "source" profile is usually set for input/incoming colour spaces such as RGB and CMYK - for untagged work that is not described by an ICC profile. So you may set say sRGB and SWOP as untagged "source" profiles for non-colour managed data, however if the work input to the system is tagged with Adobe RGB and GRACoL profiles then they would be used.

Some software workflow settings allow the device to ignore the embedded profiles and use the defined "source" profiles for incoming data (I personally think that this is akin to replacing a customer's font without their permission).

The source profile is then transformed into the device/destination/output profile.

What Tommyjt is describing in the OP sounds like a "simulation" profile. In proofing, this would simulate say Fogra39 or GRACoL or SWOP etc. A simulation or proofing profile would generally sit in-between the source and the device profile:

Source --> Simulation --> Device

Sometimes there is no source for CMYK and the simulation profile is assumed to describe the press colour.

If one is wishing to make full use of the device gamut, then they would not use a simulation profile/devicelink and simply transform the source/input colours directly into the destination/device colours.


Stephen Marsh

 

[Tommyjt]

Thank you Stephen, you are correct, what I meant was simulation profile.
I appreciate your input.

 

[rich apollo]

To take advantage of the gamut of the printer, try setting the output profile as the the simulation profile, too.

 

[Tommyjt]

I'll give it a whirl, thanks Rich!

 

[Correct Color]

Tommy,

What RIP are you using, and what RIP were you using at the old place?

It's actually pretty uncommon in large format printing to use any simulations at all. And because of that, finding where to turn them on in some RIP's can be a challenge. And it takes someone with a pretty good knowledge of large format color management to find the settings and turn them on correctly; and my experience has been guys with that knowledge aren't all that common at litho shops.

Maybe they had it right, or maybe not...

But the bottom line is that simulations are almost never used in print for pay large format. Large format is about extended gamut and big, bold color. The only standards that apply are usually proofs, and spot color definitions. And the way to achieve those is with dead accurate machine profiles that capture the full capabilities of each and every machine on each and every media.

And then the source profile is just that: The profile in which a file was sent to the RIP. So in the large format workflows I set up, I set the RIP to honor embedded profiles, and print to the destination space.

So if you ever do want to emulate some other condition, all you have to do is convert the file before you send it to the RIP.


Mike Adams
Correct Color

 

[Tommyjt]

EFI Fiery XF in both cases.
Thanks for the advise Mike!