Getting a closer match of UV flatbed prints from various print suppliers

[Rudstar]

Hi,

I have sent the same PDF file to 3 different UV flatbed print suppliers, and supplied them with the same white stock (Lab 94.0, 0.0, -2.0).
PDF file supplied as PDF/X-4, Output intent ISO Coated v2.

Our supplier’s flatbed printers are a SCREEN 1632UV, MIMAKI JFX500-2131, and HP SCITEX (7600 or 11000).

When I received the prints back, there was a very noticeable colour difference. (By eye. I have not measured using any instruments)
I realise different print quality modes will produce different colour even on the same printer, sharper text and fine lines etc.

One of our suppliers say they always print our work using the same “high quality” print mode, (which I am happy with the quality),
but I have had the same file’s colour look different on several occasions. So what are they doing differently each time to the same file?

• I’m just trying to work out if there is any extra information I should be giving the printer to get a more consistent and closer colour result from the 3 suppliers?
• What should I be asking the printer about their press, standards, colour, and the final print?
• What would you inform to a customer regarding the final print, or how would you process the file?

Thanks
Brett

 

[pauly92]

You said you're supplying them your "white stock" There can be many issues.

1, The print supplier doesn't have a specific profile for your stock so they're using a generic profile. or a profile they think would work.
2, The other print shops are probably doing the same.
3, If they have a profile made for your stock, the question is how good is it? different printer, different inks, different gamut. You can make 2 different profiles on 2 different programs with the same patch readings and get 2 different profiles that are noticeably different.

I can print on my generic paper my production mode and my quality mode and you will not be able to see the colour difference. only think you can pick is some density on some colours and a bit more grain as the drop sizes are larger.

 

[Rudstar]

Thanks Paul,
The work will be regular, so maybe I should see if our printers want to make a profile for our stock, and measure the test results to see how close or far apart they are.
This is a help for me to direct a few questions and find a way to improve the end result.
Brett

 

[pauly92]

Some shops might not bother making a profile, either they dont have the tools to, or don't want to pay someone. Unless the job is worth their time.

I how ever am usually happy to make custom profiles for other medias. But i would ask my client to provide X amount of material to use to profile with.
Just remember, not everyone is willing.

 

[Correct Color]

The entire issue you're having here is printer profiles.

In all cases, printing dots are made by a RIP using information in a profile. So it'a a profile that tells the printer what dots to make, and thus, what to print.

The question I'd ask is if you're planning on sending work that has to match to each of these printers. Because if you are, unless they're all profiled using the same profiling philosophy, and the same ICC profile-making engine, you're probably never going to get to where you want to be.

Also do you need what they print to match what you print? If so, what color management practices do you use? You'd need them basically to use the same.


Mike Adams
Correct Color

 

[Qbot]

Also do you need what they print to match what you print? If so, what color management practices do you use? You'd need them basically to use the same.

Anybody out there use Epson's as a contract proof for large format inkjet work? What if all printers used a epson as a starting point?

 

[PatPeterson]

You can also see if they are able to print *to* an industry standard; many devices allow you to build a profile based on a standard (SWOP, GRACoL 2006, etc.). If all your printers can work towards a common standard, then your prints should be a closer match to each other.

 

[Correct Color]

Pat,

You can also see if they are able to print *to* an industry standard; many devices allow you to build a profile based on a standard (SWOP, GRACoL 2006, etc.). If all your printers can work towards a common standard, then your prints should be a closer match to each other.

Yes and no.

The fact is that in large format digital of any kind -- UV, aqueous, latex, whatever -- there are no common white points or chroma values as there are in other segments of the industry. And profiles aren't made to conform to any standard, they're made -- if made correctly -- first to get all of the capability a machine's got to give in a certain condition, and then to accurately describe how the machine prints in that condition.

If that's done correctly, you can then send the machine a file in any industry standard color space and it will print to match, with the two caveats of white point of the media and gamut of that particular printer in that particular condition. However, that's also true of any file in any color space you send it.

The key is that the profile accurately describes how the device prints. If it does not, than it doesn't matter what you send it, it's going to print it incorrectly.


Qbot,

Anybody out there use Epson's as a contract proof for large format inkjet work? What if all printers used a epson as a starting point?

The "starting point" should always actually be the L*a*b* value of every pixel in the file sent to the printer. To use any device as a soft-proofing device, what you first need is an accurate profile of that device printing on your proofing media, then you need to tell that device to emulate the final output device. But that's true of any device you might happen to use. Not just an Epson.



Mike Adams
Correct Color