physical press gain in EU vs US

General Color & Graphics Press Calibration & Profiling
1

Greetings.
I am seeking some independent verification from the European members of this board or from anyone who has experience printing (packaging) in Europe and US.

My company’s goal is Global consistency in the packaging we print in Czech Republic and USA. The presses are similar, the inks are matched, the substrates roughly equivalent. At optimal densities, the US measures a gain in the mids of 18-24% but Europe insists their is 12% maximum. They say this is without curving the plates (beyond the normal adjustment).

Can anyone share their experiences in this matter?

Thanks in advance

2

Hello guyroc

I hope we are talking about offset-printing and not flexo or gravure…

In offset-printing, the european standards are based on positive
plate-making, in the USA you have negative plate-making.

Both processes are based on film and conventional plates.

Acoording ISO 12647-2, you have 6% diffenrence between positive and
negative platemaking.

E.G. Papertype 1/2 coated paper:

Europe 14% TVI for the 50% rastertone
USA 20% TVI for the 50% rastertone

If both of your printers are using CtP, they can use compensation-curves
in the RIP, if YOU as the customers clearly communicates, what kind of
data and proofs you are deliviring.

:slight_smile: Jan-Peter

guyroc schrieb:

Greetings.
I am seeking some independent verification from the European members of this board or from anyone who has experience printing (packaging) in Europe and US.

My company’s goal is Global consistency in the packaging we print in Czech Republic and USA. The presses are similar, the inks are matched, the substrates roughly equivalent. At optimal densities, the US measures a gain in the mids of 18-24% but Europe insists their is 12% maximum. They say this is without curving the plates (beyond the normal adjustment).

Can anyone share their experiences in this matter?

Thanks in advance

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homann colormanagement ------ fon/fax +49 30 611 075 18
Jan-Peter Homann ------------- mobile +49 171 54 70 358
Kastanienallee 71 ------- colormanagement.de
10435 Berlin ---------

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3

Hi JanPeter,
I was hoping you would reply.

Yes, it’s offset and I understand the positive/negative film variable having been a stripper for many years. But this is ctp and that should eliminate the gain or sharpening in plating. The files we provide are identical PDF. The inks are matched in formulation, the laydown on press is the same and the paper specifications are almost identical. Why should their be a difference in the press gain? Are you saying that the calibration in Europe for ctp is different than US?

Thanks for your input… :slight_smile:

Guy Rochford

4

Hello Guy, hello list

Imagine you are a printer and change your workflow from film to CtP.
Your customers wanting the same good quality, they had the years before.

What are you doing ?
You adjust the the CtP-process, that the printed results are the same
like on film-based processes.

For CtP, it is easy, to use different curves, to emulate e.g. positive
AND negative film-process.

If you deliver files and proofs from US to Europe, you have clear to
communicate, if you had send adjusted files and proofs for positive
process dotgain, OR if the files/proofs are for negative process and the
printer has to adjust HIS process.

Such communication has to made always BEFORE a printing project.

:slight_smile: Jan-Peter

guyroc schrieb:

Hi JanPeter,
I was hoping you would reply.

Yes, it’s offset and I understand the positive/negative film variable having been a stripper for many years. But this is ctp and that should eliminate the gain or sharpening in plating. The files we provide are identical PDF. The inks are matched in formulation, the laydown on press is the same and the paper specifications are almost identical. Why should their be a difference in the press gain? Are you saying that the calibration in Europe for ctp is different than US?

Thanks for your input… :slight_smile:

Guy Rochford

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homann colormanagement ------ fon/fax +49 30 611 075 18
Jan-Peter Homann ------------- mobile +49 171 54 70 358
Kastanienallee 71 ------- colormanagement.de
10435 Berlin ---------

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5

The same PDF goes to printing house U and E, assuming the files are not altered in any way on the way to the plate…

Printing house U gives you around 20% (probably printing to TR001)
Printing house E gives you around 12%

In the CTP workflow of printing house E, this can only be accounted for by an “intended press” curve that does not specify TR001.

They simply need to create an input with TR001 as the intended press (assuming device and actual curves are correct) and house U and E should be printing within standard tolerances.

Should they question this, point them at www.SWOP.org and tell them you are expecting the charicteristics of the TR001 specification.

Indeed. Should house E not print for the U.S. market regularly, they may not know of the TR001 specification or what printing “SWOP” means.

6

Gentlemen,
Thank you for your insights. I think what we have here is a subtle communication disconnect. We have printed packaging in EU and US for years and there has always been a difference. Because of evolving supply and inventory dynamics, EU packed product sometimes winds up in US and vice-versa. This makes the differences more visible on shelf and so we are addressing this for the sake of Global consistency.

Jan Peter is correct in his thoughts when he says the EU printer would want to maintain the results in ctp that film was producing. So when they say they have “calibrated” their plating system to positive plates, they are creating a curve, but don’t see it that way. Conversely, the US printer does use TR001 and sees midtone gains of 20% as the norm. So, with a little back and forth we have cleared this up.

Again, I thank you for your time and replies. This is a very useful forum.
See you again!
regards,
Guy Rochford[/i]