Rip and Fuji CoRes screening problem on highlights?

[hokage]

Hello everyone

I'm new here, i need help of your expertise and experience about who is the best Rip or Workflow vendor?

We are a commercial printer here in the Philippines and badly need to upgrade our rip and ctp since cause us headache (Heidelberg Metadimension, CPSI based rip with PDF 1.3 compatibility, and a unwanted line image on plate that Heidelberg service cant solve).

We consider Heidelberg, Kodak and Fuji and almost quite get Fuji when we find about their hybrid (cores) screen has a bad justification on highlights? Is is true? At the moment, we cant try the plates of fuji cores screen because they still don't have installation here. We just output their 200lpi and hopefully to run on our press just to test it after our bulk jobs.

I just hope to find a help from you guys about this as soon as possible because i'm now considering Agfa Apogee Prepress because of their hybrid great result based on studies. the problem is, they are not available here in the Philippines.......do they?

Many thanks,

Cheers

 

[baggie]

Hi Hokage
Any of the screening technologies from the major vendors should be able to produce a good result. There is nothing "wrong" with Fuji Co-Res screening that should create a problem with highlights but your printing plate and platesetter combination (not to mention the press conditions) will determine whether a fine screen ruling is suitable. Can you explain a little more about why a hybrid screen is important to you, and perhaps tell us what plate and platesetter you use?
best wishes
baggie

 

[hokage]

Hi Hokage
Any of the screening technologies from the major vendors should be able to produce a good result. There is nothing "wrong" with Fuji Co-Res screening that should create a problem with highlights but your printing plate and platesetter combination (not to mention the press conditions) will determine whether a fine screen ruling is suitable. Can you explain a little more about why a hybrid screen is important to you, and perhaps tell us what plate and platesetter you use?
best wishes
baggie

Thank you very much baggie for your reply.

We are using Agfa plates and Heidelberg Topsetter for our platesetter.
We also use 175 for our regular coated job and 250 (AM with compensation) for our magazine.
I'm evaluating Fuji for our workflow and plate setter upgrade and find out that their hybrid had a problem on highlights, please see link below

https://bib.irb.hr/datoteka/317114.XM_SCREENING_TECHNOLOGY.pdf

i think if we can run a 250 am screen on our press machine, we can run a hybrid at 175 that improve the quality and detail of an image (please correct me if i'm wrong).
thats why i think if the vendor has a problem on their hybrid, much more in their am screen? i also had a hand of a label printed in a coated paper using Fuji's 200lpi and output in their platesetter
and the highlights justify the study above.

just to make sure if other user of xmf experience the problem.

many thanks

 

[baggie]

Hi Hokage

If you are already running a 250# AM for magazine work then you should have no problem running Co-Res at the same lpi. If you wish to run a fine screen e.g. above 200# then there are traditionally some challenges:

1. More dot gain
2. Problems holding highlight and shadow detail
3. Posterisation

The first problem can be corrected by a correct dot gain curve in the RIP/Workflow. XMF, or most other workflows, will handle this for you.
The second problem can be more or less important depending on you platesetter, plate, press etc. Some combinations will result in loss of highlight and shadow detail, in simple terms because the highlight dots at high screen rulings are relatively small. However, if you are already printing 250# AM for your magazine work, assuming you are happy with the results, then clearly this is not a problem for your press. What a hybrid screen attempts to do is counter this potential problem by increasing the dot size of the smallest highlights to a minimum size e.g. the dots for a 1% tint are the same size as a 4% tint - there are just fewer of them. The downside of this is that, especially in the highlights, it can introduce what I call a "peppering" effect i.e. uneven smooth tones (the paper looks like pepper has been sprinkled on it).
The third problem has generally been overcome by the screening technologies themselves so that it does not occur. Fuji, Agfa etc.screens do not cause posterisation themselves. However, posterisation can be caused by incorrect/excessive dot gain curves and this applies to any vendor.

Reading the report in the link it seems to suggest that all the tested methods produced a good result. It seems as though they simply asked the vendors to supply a set of plates. In a real world setup those plates would have been produced using a dot gain curve which compensated for the behaviour of the actual press that the job was run on, and this would include the preservation of highlight detail. When running a set of plates that have not been calibrated for that particular press, any impression gained from the result should be treated as of only partial relevance.

If your 250# work is already good, then I don't think that you would get any improvement in 175# work by running it using a hybrid screen. Rather you should look at ensuring that the plate linearisation and press dot gain curves are correctly calibrated so that you are holding the optimum detail using an AM screen.

Hope that helps
Baggie

 

[gordo]

[snip]I'm evaluating Fuji for our workflow and plate setter upgrade and find out that their hybrid had a problem on highlights, please see link below

https://bib.irb.hr/datoteka/317114.XM_SCREENING_TECHNOLOGY.pdf
[snip]

You can safely ignore the "information" in the PDF "Original scientific paper" from the University of Applied Sciences, Varaždin, Croatia.

It is not science. The tests were poorly designed and executed. It contains a lot of misinformation as well as repurposed vendor marketing posing as technical information. Do not use it as a basis for any purchase decision you make.

best, gordo

 

[hokage]

Wow, it certainly a big help

Thank you very much baggie

and thank you also for Gordo for the inputs.

you are a big help guys in our evaluation.



thank you, thank you