Coated & Uncoated Pantone Simulation on Digital Presses/Copiers

[Nate]

Say you get a mailing job with several different items that will be printed on different processes and then mailed together. Maybe you have a brochure that will be printed offset on a premium coated stock, an uncoated envelope that will also be printed offset, and finally an insert card that will be printed digitally on uncoated stock.

All of the items include the same logo spec'd in their digital file as 5405 C. For the sake of this example, both offset jobs are being printed with the solid pantone ink--not a 4-color approximation. For the offset jobs then, there's no decision to make on converting that color--5405 is the same ink mix whether it winds up on coated or uncoated stocks.

For the digital item however, it's a bit of a different story. Since toner stays on top of the sheet with no absorption like offset inks, colors spec'd in a digital file as Pantone Coated inks are reproduced very similarly whether printed on a coated or uncoated stock (not perfectly identical, but much closer than most solid Pantone inks between their coated and uncoated reproduction on offset processes). This means that even though it'll be printing on an uncoated stock, the digital press can simulate the Coated pantone swatch just as accurately as it can the Uncoated swatch. 

[Joe]

Pantone has both a solid coated and uncoated recipe. Designers rarely pay attention to which one they are using though. They just pick the first one they run across. But pressman should be mixing for whatever type of paper they are using.

[Nate]

Definitely true that designers rarely pay attention to which one they are using.

Are you sure about having different coated and uncoated recipe's though? I'm talking mixing bases--not 4-color builds.

Looking at my formula guides right now seems to confirm that they have the same recipe. (5405 for example is Reflex Blue 31.8, Yellow 4.6, Black 13.6, Transparent White 50)

[Joe]

I'm not really sure. I don't mix ink. I just figured if they have both a coated and uncoated they would be slightly different. But maybe that is only for the CMYK mix.

[Farabomb]

Nate is right, I just checked my books and the mixes are the same. I wasn't aware of that.

And silly Joe, thinking pressmen can read. That's like thinking a designer knows the difference between pms 455C and 455U.

[Joe]

Well it is a theoretical assumption. But don't let them fool you. They can read what time happy hour is.

[Joe]

Back to Nate...were you asking something in the original post or just posting for info?

[Nate]

I guess the gist of the question is, given that a digital press can simulate a coated Pantone swatch on an uncoated stock, does anyone actually do that? Or does everyone prefer to always use Uncoated swatches for uncoated stocks--even when printing digitally.

I would assume at first that the best option would be to only send Coated Pantone colors for coated jobs and Uncoated Pantone colors for uncoated jobs, as this would simulate the behavior of physical Pantone inks. This would be the most straight-forward, common-sense approach.

The downside to that approach though is that you can often get a more subjectively pleasing result by instead simulating the coated inks with their extra depth and saturation. In most cases I would consider this to be an improvement, but the subjectivity means that it's impossible to know for sure which the client would prefer without showing samples and asking them to make the call--especially in situations like the one I've outlined in the original post where you have multiple different stocks that will ultimately be viewed together as part of a single mailing.

[Tracy]

We just got a new Konica Bizhub, and I'm trying to figure this out too.
It looks to me like using Coated spots on uncoated match to previous printing better.

This is a copier tho, not a digital press. (well they say it is but)

[Nate]

Thanks for the input Tracy. Good to know I'm not alone in this conundrum.

It just occurred to me by the way that I've got a bit of a different problem to solve before I can reliably set up a standard procedure for handling spot colors.

Our iGen operator keeps a library of spot color definitions that could cause some problems. Basically, whenever a spot color doesn't match a previous job, he'll edit his definition of that spot color to bring it in line with the previous run. Of course, if the previous run didn't actually match the standard, that means we've now changed that spot color definition to a non-standard appearance (which will bite us in the ass the next time a different job uses the same spot color.

I think I need to talk to our digital operator about archiving his current spot-color library as a "legacy matching" library that we can go back to it as needed, then resetting the definitions to the default L*a*b standards.

[wonderings]

I don't care much if it is Pantone C or Pantone U when printing digitally. When I am designing I still design with the right pantone in mind, I can be a bit anal about that.

When it comes to printing a pantone colour digitally, rarely do I find it is close to my swatch book and most times I am trying to match what they did on press. I treat the pantone like a spot colour and make adjustments to the pantone colour till I get it to where I want to be.

[Tracy]

So your adjusting to process?

For Nate, can you explain what you said about the operator changing the definition?
This may be helpful for me to understand

[wonderings]

Looking at the pantone colour library in Command workstation, it has different makeups for pantone colours C and U. On our Versant 2100 Pantone Yellow (default setting) for example is made up:

Pantone Yellow C
0 C
11 M
100 y
0 K

Pantone Yellow U
.5 C
13 M
96.5 Y
0 K

I generally will use the same makeup on an uncoated stock as what I setup for a coated stock and the results are always very close. I prefer keeping files with spot colours/pantone colours, it makes it much easier for me to adjust the colour if need be. If the job is CMYK, well not much you can do on the RIP end if you need to tweak something.

[Fontaholic]

If I take the same Pantone spot color and run it on our Xerox CLC 700 using two different color profiles (one for Coated stock, the other for Uncoated stock), I usually get two very different results.

As someone mentioned upstream, using the Coated color profile to run jobs on uncoated stock, generally yields the results that most closely match the Pantone spot color swatches.

That being said, some Pantone colors just will NOT reproduce on a color copier -- sorry, digital color press! -- or even on a traditional four-color press, with any degree of accuracy.

We have a swatch book here called "PANTONE Color Bridge Coated" which shows the different PMS colors both in their original spot color format, and their nearest CMYK equivalent (which in some cases isn't very near at all).

Cheers,
John the Fontaholic

[Farabomb]

Very true, there are some colors that just can't be replicated with 4c process.

Doesn't matter if you show the customer the bridge book. His last printer never had a problem.

How come nobody has the balls to ask why they are not using that mythical printer? Probably because that printer got tired of their B.S. and fired him as a customer.