Prinergy, Plates and Calibration

[lostmind]

We're running Prinergy and Prinergy EVO with an Acheive Platesetter. I've asked this question of printing friends before and not really gotten an answer. Do you need to calibrate the Sonora plates occasionally and if so, what's the process? I used to calibrate plates all the time when I had RamPage but those plates were totally different then. Thanks for any help!

 

[gordo]

What do you mean by "calibrate"?

 

[lostmind]

Hi Gordo. What I mean is in the "old days" we had to read the dots on the plates making sure the screen percentages were correct and if not, we made appropriate adjustments. My understanding with the Sonora process free plates (and maybe other brands) that this is no longer required correct? From then on, you can have a curve to allow for dot gain etc. perhaps if you were fingerprinting a press maybe but nobody's ever mentioned to me that there is anything that needs to be done now as far as the plates being "out of calibration" as my pressman is trying to tell me.

 

[chriscozi]

Hi Gordo. What I mean is in the "old days" we had to read the dots on the plates making sure the screen percentages were correct and if not, we made appropriate adjustments. My understanding with the Sonora process free plates (and maybe other brands) that this is no longer required correct? From then on, you can have a curve to allow for dot gain etc. perhaps if you were fingerprinting a press maybe but nobody's ever mentioned to me that there is anything that needs to be done now as far as the plates being "out of calibration" as my pressman is trying to tell me.

LOL.
Who told you not to 'calibrate' the plate?
It all comes down to the IMAGING system (laser) staying the same and the plate emulsion staying the same.
So if your plate provider 'calibrated' your 'laser' device then "as long as" there are no changes in the laser intensity OR the plate emulsion you should be good.
BUT
That assumes no changes.
The old test confirmed your laser and chemistry and emulsion.
So you CAN run a 'test' plate and run it up on the press as long as you ran the 'same' test plate when you started using these plates.
Get calibration software and hardware.
Any time the press can't match the 'calibrated' proof - run a calibration plate.
And this REQUIRES the pressman to make his machine print to spec.
My 2 cents.
YMMV

 

[lostmind]

LOL.
Who told you not to 'calibrate' the plate?
It all comes down to the IMAGING system (laser) staying the same and the plate emulsion staying the same.
So if your plate provider 'calibrated' your 'laser' device then "as long as" there are no changes in the laser intensity OR the plate emulsion you should be good.
BUT
That assumes no changes.
The old test confirmed your laser and chemistry and emulsion.
So you CAN run a 'test' plate and run it up on the press as long as you ran the 'same' test plate when you started using these plates.
Get calibration software and hardware.
Any time the press can't match the 'calibrated' proof - run a calibration plate.
And this REQUIRES the pressman to make his machine print to spec.
My 2 cents.
YMMV

No, I do agree with you regarding in the event that there is an issue with the laser although the Kodak guy that did the last PM really didn't offer much of an explanation as to test for it. Unfortunately we didn't keep a test plate or sheet to go by. As far as the pressman goes, he's all over the place with color...if there was an issue with the plates, the entire print job would reflect bad calibration or an issue with the laser than what's totally inconsistent throughout.

 

[gordo]

No, I do agree with you regarding in the event that there is an issue with the laser although the Kodak guy that did the last PM really didn't offer much of an explanation as to test for it. Unfortunately we didn't keep a test plate or sheet to go by. As far as the pressman goes, he's all over the place with color...if there was an issue with the plates, the entire print job would reflect bad calibration or an issue with the laser than what's totally inconsistent throughout.

I think you need to calibrate your pressman.

Normally the person that's doing the initial installation would set it up to deliver a robust image on the plate and explain how to measure the plate should you wish to do so. Typically the plate imaging will be consistent and only a concern when using a new batch of plates.

You should have in your files an unused test plate with all tone patches and any other relevant info written on it. You should also have a sample printed test sheet made from a duplicate plate with all measurements written on it. You should have taken micro photos of the press sheet halftone dots.
That package becomes your gold standard that you can refer to if presswork fails to meet the target.

The goal of the process is not to print/make color on the press.

Instead, the goal of the process is to reproduce as accurately as possible the image that is in the binary bitmap that will be imaged on plate and then the press sheet.
If you have set up your system properly then the color will fall into alignment with the proof. Only small adjustments may be needed to compensate for things like inline ink coverage, press temperature, etc.

The pressman should first be concerned about coming up to target SIDs and target water levels, squeeze, etc. Only once the press is set up to shop targets should he be concerned with color. Small ink density shifts may be needed to best align the presswork to the proof.
Anymore than that small adjustment in SIDs means a discussion between Prepress and pressroom need to happen to understand and correct the problem.

On a sidebar - many publication work (newspapers, magazines, etc.) only run to the numbers and do not use proofs for color.

 

[G5MacMan]

"I think you need to calibrate your pressman."

 

[johnny_jay]

If the color is all over the place, is the press closed loop color? Running to house densities?

When is the last time you fingerprinted the press?

 

[johnny_jay]

I should have also added that we run 3 presses with 2 plate setters. We do not linearize our plates but often run checks to confirm nothing has changed. One plate line has an auto scanner for all plates and the other line has at least 3 plates checked per shift.

We run to the G7 method on press, and fingerprint as often as we feel is needed. We are a Prinergy/InSite/PressProof shop as well but do not run Kodak plates or hardware.

All presses are closed loop color, all but one has grey balance control on press.

 

[gordo]

We do not linearize our plates but often run checks to confirm nothing has changed.

YES!

 

[lostmind]

Thanks everyone for your responses. Gordo, I just recently found an unused test plate wrapped in paper next to my desk and the wall but there's nothing written anywhere or a sample of anything. I really don't remember when it was put there or by whom. My pressman has been pushing the owner about me changing the tonal curves because he's running too heavy on the black and says he's been printing to the numbers. From doing some research, it appears that when we were running Prinergy EVO and changed over to the full version of Prinergy, they migrated the (Harmony) tonal curves from EVO to Prinergy (8). We also changed from a Magnus 400 to an Achieve Platesetter but still keeping Kodak plates. These are the same tonal curves that I'm aware of we've used for the last 14 years. I have tried unsuccessfully for years to have the press fingerprinted but it all falls on deaf ears. We fingerprinted the presses at the last shop I worked at so I know the process. I don't even have a spectrophotometer even if I could adjust the curves. Believe me it's frustrating. The question is...would adjusting the tonal curves even fix the saturation issue on the black unit or is it something wrong with the press itself?

 

[gordo]

Thanks everyone for your responses. Gordo, I just recently found an unused test plate wrapped in paper next to my desk and the wall but there's nothing written anywhere or a sample of anything. I really don't remember when it was put there or by whom.

Mystery plate? Recycle it.

My pressman has been pushing the owner about me changing the tonal curves because he's running too heavy on the black and says he's been printing to the numbers

How the press is running usually doesn't mean very much to management.

I have tried unsuccessfully for years to have the press fingerprinted but it all falls on deaf ears.

The approach I suggest when asking management for change has worked well in many shops.

Make your pitch based on economics - after all, no profits means no business and hence no jobs (management included.()

First, treat the press fingerprinting as a real job and get estimating to cost it out.

Armed with that estimate go and see management.
Explain that the current set up is reducing company profits due to longer press make-ready times and materials than necessary. It also lowers press productivity and hence press availability/utilization.

Give management the cost estimate to do the fingerprinting that will resolve the press problems.

That's it. You've done your job. You've described the problem (lost profits and productivity) and provided the solution (fingerprinting). It's now out of your (and the pressman's) hands/concerns. If there are any issues about presswork moving forward they are not your problem. They are management's.

We fingerprinted the presses at the last shop I worked at so I know the process. I don't even have a spectrophotometer even if I could adjust the curves. Believe me it's frustrating. The question is...would adjusting the tonal curves even fix the saturation issue on the black unit or is it something wrong with the press itself?

A spectro would be nice but you can just use a densitometer to build your curves.

 

[lostmind]

Thanks Gordo! Appreciate the help. I do remember the days of using a densitometer to measure the plates...just a long time ago.

Question to all...what do you consider an "old" press? Owner thinks 25 years is too old to fix.

 

[gordo]

Thanks Gordo! Appreciate the help. I do remember the days of using a densitometer to measure the plates...just a long time ago.

Question to all...what do you consider an "old" press? Owner thinks 25 years is too old to fix.

A small observation, the age of a press is typically measured by number of impressions rather than years. Even Heidleberg windmill presses from the 1920s are still being fixed and kept running.

 

[lostmind]

A small observation, the age of a press is typically measured by number of impressions rather than years. Even Heidleberg windmill presses from the 1920s are still being fixed and kept running.

We actually have a couple Windmills. The press I'm referring to I'm told has 47m impressions. The counter says 23.5m but I was told to double that which I'm not sure why. It's a Komori Lithrone 28.