Screen Ruling for yellow plates

[SilvaJr]

We are running Prinergy Evo 5.1.6.11 with a Trendsetter VLF 5067.

Tiff creation is being generated with ElipticalIP 150lpi to be used in a Heatset Web press.

Using a digital microscope, we noticed that the yellow surface has 175lpi instead of 150lpi according to our Process Template. Is there any valid reason why Kodak is increasing the screening on yellow by default?

Thanks in advance.

 

[gordo]

We are running Prinergy Evo 5.1.6.11 with a Trendsetter VLF 5067.

Tiff creation is being generated with ElipticalIP 150lpi to be used in a Heatset Web press.

Using a digital microscope, we noticed that the yellow surface has 175lpi instead of 150lpi according to our Process Template. Is there any valid reason why Kodak is increasing the screening on yellow by default?

Hopefully Kodak will answer this question.
In general, Yellow is typically run at a higher lpi with most workflows - not just Prinergy.
Each vendor will use their own method but the usual lpi for Yellow is about 108% of the lpi of the other colors. So if you are using 150 lpi the Yellow would probably be 162 lpi.
The purpose for the higher Yellow lpi is to reduce the moiré caused by the fact that Yellow is angled just 15° from the next process color (usually C at 105°)

best, gordo

 

[SilvaJr]

Thank you Gordo, for your quick reply.

I just would like to check if this can impact our color standardization since we are printing under ISO 12647..

Thanks,

 

[gordo]

Thank you Gordo, for your quick reply.

I just would like to check if this can impact our color standardization since we are printing under ISO 12647..

Thanks,

No, it will not visibly impact your color standardization under ISO 12647. The higher lpi for Yellow is pretty much standard in all AM/XM screening from all vendors.

best, gordo

 

[SilvaJr]

Hi Gordo, thank you for your input.
In fact, I'm interested to see if wearing in longer runs it will be an issue on yellow 175 lpi plates. Thanks

 

[gordo]

Hi Gordo, thank you for your input.
In fact, I'm interested to see if wearing in longer runs it will be an issue on yellow 175 lpi plates. Thanks

If I understand you correctly - no, it should not be an issue. If it was you'd have heard about it by now since the higher Y lpi is pretty much standard across most, if not all, vendors.

best, gordo