47L Paper white

[samwks]

I have use EPSON print the 47L proof to our client,then client OK,our printing results are not satisfactory,what the problem, is the paper white ? and how to solve it in prepress?
Thanks

 

[gordo]

I have use EPSON print the 47L proof to our client,then client OK,our printing results are not satisfactory,what the problem, is the paper white ? and how to solve it in prepress?
Thanks

In what way are your results not satisfactory?

gordo

 

[Stephen Marsh]

Can you measure a colour bar and qualify that the proof conforms to F47? Can you do the same for the print?

Stephen Marsh

 

[Ferran]

Client's approval is not relevant. It is important to know if the proof and the print results are correct, so I agree with Stephen, you need to be able to measure them. It is also important the proofing substrate used. I have extracted this text from the eci.org website: "Another specific characteristic applies to proofing for offset printing on uncoated stock: Using a semi-matt proofing substrate, commonly used for “coated” proofs, will yield a poor visual proof to print match even in the case of an excellent metered proof evaluation. The use of uncoated proofing stock results in the best possible metered match with the aim values of the characterization data set and the best possible visual proof to print match."
And for the paper white, some vendors have solutions; f.i. GMG and the Paper Adaption Tool for the calculation of the paper tint correction, resulting in a better match of proof and print.

 

[samwks]

The problem is client consider you give a standard 47L proof , printer why can't print out color proof similar results?because we can't to change paper and ink to print.

 

[Stephen Marsh]

Client's approval is not relevant. It is important to know if the proof and the print results are correct, so I agree with Stephen, you need to be able to measure them. It is also important the proofing substrate used. I have extracted this text from the eci.org website: "Another specific characteristic applies to proofing for offset printing on uncoated stock: Using a semi-matt proofing substrate, commonly used for “coated” proofs, will yield a poor visual proof to print match even in the case of an excellent metered proof evaluation. The use of uncoated proofing stock results in the best possible metered match with the aim values of the characterization data set and the best possible visual proof to print match."
And for the paper white, some vendors have solutions; f.i. GMG and the Paper Adaption Tool for the calculation of the paper tint correction, resulting in a better match of proof and print.

Many printers may try to “proof” uncoated work on a cheap matte coated imposition paper, that does not pass a F47 verification…which is why they end up proofing F47 on a semi matte proofing media that would normally serve for F39 proofing.

As far as I can remember, both F39 and F47 have the same white point target value (obviously a gloss or semi gloss substrate looks different to an uncoated media, even if inkjet colour management is limiting the colour gamut of the F47 simulation).


Stephen Marsh

 

[Ferran]

I agree Stephen, we have always used a semimatte substrate for proofing, but we were not happy enough with the "look and feel" of F47 proofs compared to the press sheets, and because proofs must simulate the expected printed result as closely as possible now we are also using the GMG ProofPaper matte 140gsm for simulation of uncoated papers. So far so good.

And forgot to mention, but data (PDF) has to be well prepared for being printed on uncoated paper. We usually have to make color conversions to get new separations when printing on uncoated. Designers normally use a coated ICC profile for creating cmyk separations because they ignore the substrate used for printing. It is not their fault, it’s just how it works in the real word.