Printing outside of standard conditions

[Stefan Ohlsson]

I'm trying to set a proofing workflow for a retoucher. He works mainly for photographers that publish their images in different high end fashion magazines and one of the is printing on a uncoated paper. The magazine says that they are using PSO Uncoated as their CMYK-profile, but the black is so much deeper than it should be according to that standard. Of course he and his photographers would like to have a proof that reflects this result. But is there a way to adjust that profile and change the black to something more matching that the magazine uses. The printing company doesn't answer my question, but they are Italian, so no surprise there.

Best

Stefan
www.profiler.nu

[digitaldog]

In a word, not easily. You would need the measurement data, the same profile creation software to do this any kind of justice and even then it’s risky and not a very good idea. In fact the idea of doing anything in CMYK like this makes me pretty nervous for a number of reasons.

[Tim Lookingbill]

I'm trying to set a proofing workflow for a retoucher. He works mainly for photographers that publish their images in different high end fashion magazines and one of the is printing on a uncoated paper. The magazine says that they are using PSO Uncoated as their CMYK-profile, but the black is so much deeper than it should be according to that standard. Of course he and his photographers would like to have a proof that reflects this result. But is there a way to adjust that profile and change the black to something more matching that the magazine uses. The printing company doesn't answer my question, but they are Italian, so no surprise there.

Best

Stefan
www.profiler.nu

Whose black is so much deeper? The retouchers? or the way the magazine prints absolute black?


Why not just find images online or directly from the source that appear in that uncoated paper stock magazine and see how deep the RGB black extends to and compare to what it looks like in the magazine. It may not be as big an issue as you're describing.

[Stefan Ohlsson]

Whose black is so much deeper? The retouchers? or the way the magazine prints absolute black?


Why not just find images online or directly from the source that appear in that uncoated paper stock magazine and see how deep the RGB black extends to and compare to what it looks like in the magazine. It may not be as big an issue as you're describing.

The retoucher proofs the image according to the standard that the magazine says that they use for their separation from RGB to CMYK. I have the retoucher's image and the black point is set correct. The black on the proof comes out according to the standard for PSO Uncoated and the proof is validating OK with an average Delta E of 0,68 and a maximum of 1,8. Very tight, I might say. The black patch has a L*value of 23. But when he got the magazine back, the blacks were much deeper in the print than on the proof. I measure a L*value of 15 when I average several points in an image with a pitch black background.

The photographer of course is upset when the proof is so much grayer than the printed image. The retoucher wants a proofing workflow that reflects the actual black that he can expect in the magazine.

[Tim Lookingbill]

The retoucher proofs the image according to the standard that the magazine says that they use for their separation from RGB to CMYK. I have the retoucher's image and the black point is set correct. The black on the proof comes out according to the standard for PSO Uncoated and the proof is validating OK with an average Delta E of 0,68 and a maximum of 1,8. Very tight, I might say. The black patch has a L*value of 23. But when he got the magazine back, the blacks were much deeper in the print than on the proof. I measure a L*value of 15 when I average several points in an image with a pitch black background.

The photographer of course is upset when the proof is so much grayer than the printed image. The retoucher wants a proofing workflow that reflects the actual black that he can expect in the magazine.

OK, now I understand. That's a huge difference for L* black level. Offset printing on uncoated paper might be a bit hard to control consistently due to current humidity levels and other conditions unforeseen only to that particular press run.

Have you checked whether this happens all the time with older magazine issues by checking other folks images as I suggested above? It's been decades since I had anything printed on commercial press so I wouldn't know how to fix this digitally much less with ICC workflows.

I'm assuming the images look good with the darker black than the grayish, but if you're going to be using this magazine in the future you might want to be talking to someone closest to the press that is in charge of quality control. Might find out if the magazine optimizes the CMYK images for their particular press or for different presses spread across different locations around the world.

Maybe you'll get more help here from other contributors.

[Czornyj]

But when he got the magazine back, the blacks were much deeper in the print than on the proof. I measure a L*value of 15 when I average several points in an image with a pitch black background.

My wild guess is that it's not uncoated paper printed on sheet-fed offset press, but MFC printed on web heatset - it has exactly L* value of 15. Try FOGRA 41L based PSO_MFC_Paper_eci.icc (eci.org) profile as reference profile and check if the proof matches the effect better.

[Stefan Ohlsson]

My wild guess is that it's not uncoated paper printed on sheet-fed offset press, but MFC printed on web heatset - it has exactly L* value of 15. Try FOGRA 41L based PSO_MFC_Paper_eci.icc (eci.org) profile as reference profile and check if the proof matches the effect better.

It's odd when the printer doesn't want to communicate what profile they are using, as it was some sort of trade secret. Thank's for good advice, I'll try that one and report back. I know that they do web printing as well, so you're probably right.

Best

Stefan
www.profiler.nu

[Stefan Ohlsson]

Have you checked whether this happens all the time with older magazine issues by checking other folks images as I suggested above? It's been decades since I had anything printed on commercial press so I wouldn't know how to fix this digitally much less with ICC workflows.

Yes, they have a very consistent look through the different issues that I browsed. So it's not a problem with the magazine, but my proofs look bad and my retoucher gets complains from the photographers that he is working for.

Best

Stefan
www.profiler.nu

[Czornyj]

It's odd when the printer doesn't want to communicate what profile they are using

Probably he doesn't have a clue. Unless he doesn't make proofs or use some ink saving color server, he doesn't have to use any profile.

[Stefan Ohlsson]

Probably he doesn't have a clue. Unless he doesn't make proofs or use some ink saving color server, he doesn't have to use any profile.

This is a major Italian printing company, not some small cellar printer. But the Italian printers are a bit different to work with, extremely good with the press, but new things like ICC profiles and such shit ;-)

Best

Stefan
www.profiler.nu