Plate switch from Fuji to Trillium

[rmac2125]

Hey,

Has anyone made the switch from Fuji LH-pi lates to Kodak Trillium.
I am currently having plate calibration issues.
Our one CTP device images both plates and the plate readings are the same, but on press they print differently. The kodaks print heavy.
Using harmony I've adjusted the target curve to compensate for this and I was hoping this would be sufficient, so I wouldn't have to recalibrate all my press curves.
Can you share some of the problems and solutions in making the switch or if they have experienced the same issue.

Thanks

Rob Mac

[Kevin@Kodak]

Hey,

Has anyone made the switch from Fuji LH-pi lates to Kodak Trillium.
I am currently having plate calibration issues.
Our one CTP device images both plates and the plate readings are the same, but on press they print differently. The kodaks print heavy.
Using harmony I've adjusted the target curve to compensate for this and I was hoping this would be sufficient, so I wouldn't have to recalibrate all my press curves.
Can you share some of the problems and solutions in making the switch or if they have experienced the same issue.

Thanks

Rob Mac

Hi Rob - welcome aboard!

Firstly, Trillian SP is a negative-working plate (i.e. write-the-image), versus many other commercial plates on the market that are positive-working (i.e. write-the-background). A negative plate will generally be slightly fuller when uncalibrated than a positive plate will be. You do mention that you've calibrated the plates back to linear though.

There are other variables at play here, but my first suggestion would be to ask your Kodak rep for help. We'll certainly do what we can to get things running smoothly for you - let me know if you need any help or contact numbers.

Kevin.

[gordo]

[snip]
Our one CTP device images both plates and the plate readings are the same, but on press they print differently. The kodaks print heavy.
Using harmony I've adjusted the target curve to compensate for this and I was hoping this would be sufficient, so I wouldn't have to recalibrate all my press curves.

One small detail for the sake of accuracy in terminology. In Harmony (and perhaps other systems) the "target curve" represents the tonal or dot gain characteristic of the printing that you want to match. You do not adjust the target curve to compensate for how your plates print.

The "current curve" represents the tonal value or dot gain characteristic of your current printing.

The "calibration curve(s)" curve represents the adjustment needed to the tone specified in the digital file so
that your target is achieved on press.

And, disagreeing with Kevin here, there is usually no need to bring the plates to linear unless linear plates are what you need in order to hit your target curve.

best, gordo

[rmac2125]

Hi Gordo,

Harmony curves are, as you know, Current + Target = Calibration
I have current curves that are skewed for the each press / stock etc / line screen etc...
Target curve is the same curve for each press to achieve consistent results on press.
My thinking was to skew the target curve so that I wouldn't have to recalibrate for press, stock, line screen.
I was trying to find an easy route to my calibration issues, instead of doing the whole process of calibrating for these new plates.

[gordo]

Hi Gordo,

Harmony curves are, as you know, Current + Target = Calibration
I have current curves that are skewed for the each press / stock etc / line screen etc...
Target curve is the same curve for each press to achieve consistent results on press.
My thinking was to skew the target curve so that I wouldn't have to recalibrate for press, stock, line screen.
I was trying to find an easy route to my calibration issues, instead of doing the whole process of calibrating for these new plates.

This is a Kodak customer support issue which I don't do (maybe someone else on the forum will).

That being said, I'm pretty sure that you can/should leave your target curve as is and have Harmony recalculate your calibration curves based on your current curves without the need to do a bunch of press tests.

Hopefully someone from Kodak will show you how.

sorry, gordo

[Kevin@Kodak]

[...snip]And, disagreeing with Kevin here, there is usually no need to bring the plates to linear unless linear plates are what you need in order to hit your target curve.

best, gordo

Thanks Gordo - you're absolutely correct. I made that comment assuming that linear was what his previous plates produced (or were calibrated for), and he was simply trying to match the previous condition so that he achieved the same end result on press. Linear is not necessarily the ideal or required condition - it's just common because it's "simple".

Kevin.

[mlindner]

Bob,Gordo, Easy easy fix. First do not touch "current, target, calibration" they stay the same.
If you read the difference be between the Fuji and Trillian, make a curve to compensate.
Our Trillian was to full by 6% at the 50. Made a curve with a -6% @ 50, named it Trillian correction.
Then when you go to plate, the Calibration and Screening screen, go down to CALIBRATION and put
in your Trillian correction curve, below that PRINT CURVE, put in you normal paper curve i.e. -5@40 etc.
Your done.....We tested Sword verses Fuji, Trillian and Agfa, all at the same time each with a correction curve, worked great. Did not have to touch hundreds of paper and job specific curves.

Mark
Prepress Manager
Worzalla Publishing
mlindner@worzalla.com