tvi on plates

ar17

Well-known member
when applying tvi curves on plates, do we need to also apply the curve on the control bar? i have established the curves and actually applying it on my CtP but my control bars are sent as fixed 1bit file so there is no curve being applied... what is the right approach in applying curve during platemaking?
 
Re: tvi on plates

I feel that you'd want the color bar to be representaive of the live area of the press sheet, so yes, the control bar should have the same compensation as the rest of the job. That said, I know of other companies, some quite reputable, whose process control software alledgedly only works with typical screening, so even when they're using FM screeing, they utilize a linear AM 150 lpi color bar. However, in this scenario, its possible that there are proccess control issues that affect FM screeing before it would be noticed on an AM color bar, so its risky in my opinion.

In any event, I would also recommend that a plate control element be imaged that shows both the default exposure ("linear") response of the plating system, as well as the Rip compensation applied to the file, so you at least know what's what on the plate.
 
Re: tvi on plates

I prefer to have the colorbars un-curved, so that they provide more accurate feedback about press performance. However, if you have a gray balance patch (or target), that MUST be curved.

rich
 
Re: tvi on plates

Mike:
The original digital plate control bars from UGRA and FOGRA, even GATF, were stacked, with one bar to represent the uncorrected state, for plate process control, and the other to reflect the curve applied at the RIP. These were "smart" targets, but I'm not sure they always worked. Are you talking about a target provided by the manufacturer, or your own invention?
John Lind
Cranberry Township, PA
724-776-4718
 
Re: tvi on plates

>The original digital plate control bars from UGRA and FOGRA, even GATF, were stacked, with one bar to represent the uncorrected state, for plate process control, and the other to reflect the curve applied at the RIP. These were "smart" targets, but I'm not sure they always worked. Are you talking about a target provided by the manufacturer, or your own invention?

I've used the GATF one, and it actually didn't work correctly...the "uncorrected" portion was always compensated by the Rip. This was an old version though. We now use a target provided by Creo that works as advertised... but on rare occasions a file will fail at the Rip until the target is removed from the file and resent.
 

PressWise

A 30-day Fix for Managed Chaos

As any print professional knows, printing can be managed chaos. Software that solves multiple problems and provides measurable and monetizable value has a direct impact on the bottom-line.

“We reduced order entry costs by about 40%.” Significant savings in a shop that turns about 500 jobs a month.


Learn how…….

   
Back
Top