linearization in a digital plate

[RJRABIYA]

Dear Friends

I have been working on setting of a digital plate on a new violet system. could anyone please let me know the tolerance of dot% on the plate after setting the calibrations.
What is the maximum permitted dot variation on a plate during calibration.

RJ

 

[gordo]

Dear Friends

I have been working on setting of a digital plate on a new violet system. could anyone please let me know the tolerance of dot% on the plate after setting the calibrations.
What is the maximum permitted dot variation on a plate during calibration.

RJ

Calibration is not linearization.
Calibration is required. Linearization is probably not required.
After calibration a press run is done to determine the tone response on press.
That tone response on press is used to build a press correction curve for the plate so that the correct tone response will be achieved on press.
That correction curve may, or may not, make the plate linear.

best, gordo

 

[Armya Inc]

Dear Friends

I have been working on setting of a digital plate on a new violet system. could anyone please let me know the tolerance of dot% on the plate after setting the calibrations.
What is the maximum permitted dot variation on a plate during calibration.

RJ

Your Violet plate is Polymer( What Brand?) or the Silver Halide? What is your CTP?

 

[Ozkan Hangisi]

Dear Friends

I have been working on setting of a digital plate on a new violet system. could anyone please let me know the tolerance of dot% on the plate after setting the calibrations.
What is the maximum permitted dot variation on a plate during calibration.

RJ

Many printinghouses accept ±2 in tolerance for midtone measurements.

Regards

 

[Armya Inc]

Dear Friends

I have been working on setting of a digital plate on a new violet system. could anyone please let me know the tolerance of dot% on the plate after setting the calibrations.
What is the maximum permitted dot variation on a plate during calibration.

RJ

The following Applied to Violet Plates:

Violet Plates compared to Thermal Plates are more stable for Background toning and Exposure variations.
Calibration through dot measurement in reflection on the plate
-This ensures that a particular dot percentage requested by the pre-press
application on the front- end will show up exactly the same on the printed sheet.
-It does so by compensation for dot gain or dot loss on the plate generated by the
platesetter and the plate/chemistry combination.
-In practice, calibration means nothing more than entering the measured and the
wanted dot percentage in a calibration programme with their platesetters.
-Exposure setting and calibration can be determined by reading the background
density values and halftone dot percentages with a good densitometer.
-Acceptable results also can be achieved with the new planimetric dot area
meters,e.g. the CC Dot type 2,3 and 4 (+/-1%between 10%&90% dot accuracy).
-Recommendations:
-Always measure without Yule-Nielsen factor (factor = 1).
-Always measure without gum on the plates.( Gum isn't the Finisher in case of Silver Halide Violet Plates )
-Always use the same densitometer for the readings.
-Other exposure targets are either supplied by the platesetter manufacturer(Agfa Digiwedge) or by
organisations such as Fogra or GATF .

Hope this will Help!

 

[gordo]

Prepress operators are expected to make sure that plates delivered to the press are linear, with a typical tolerance of around 2%.

Good post but a small correction.

Prepress operators are not expected to make sure that plates delivered to the press are linear, with a typical tolerance of around 2%. Prepress is expected to deliver plates that are consistent and that includes a tone reproduction that will deliver the correct final tones on press. That may, or may not be a linear plate.

best, gordo

 

[Armya Inc]

Calibration is not linearization.
Calibration is required. Linearization is probably not required.
After calibration a press run is done to determine the tone response on press.
That tone response on press is used to build a press correction curve for the plate so that the correct tone response will be achieved on press.
That correction curve may, or may not, make the plate linear.

best, gordo

I removed that post. Gordo, Can you please provide us with detailed information on Dot Gain and Linearization.

 

[gordo]

I removed that post. Gordo, Can you please provide us with detailed information on Dot Gain and Linearization.

Those are big subjects.

Detailed info is here: Quality In Print: dot gain

Briefly, Dot gain (and loss) is part of the print process. It does not have the importance it once had since, with CtP, you can have whatever "dot gain" you want. Just apply the required press curve to the plate to achieve it.

Linearization also doesn't have the importance it once had. In a film workflow, linear film was the standard file exchange format. That's been replaced by PDFs. Linearization is basically a press curve applied to the plate. If it enables you to achieve the correct tone reproduction on press - then it's good. If not, it has no use.

best, gordo