Harmony curves in Prinergy

[Angie]

Hello all-
I have what I hope is two simple questions, we have a one curve, measuring black, harmony curve applied to our plate output which just linearizes the plates. We are going to start the process of becoming G7 certified which means I will have to alter all four colors individually. Here are my questions: Is there a way to save/use the existing calibration curve as my new current curve? If so, I then plan on creating a new, CMYK curves, target curve which according to the users manual should work, any thoughts on this process? I have been knee deep in the users manual for days and quite frankly it is written poorly. Thanks in advance for any help you may have.

 

[gordo]

Hello all-
I have what I hope is two simple questions, we have a one curve, measuring black, harmony curve applied to our plate output which just linearizes the plates. We are going to start the process of becoming G7 certified which means I will have to alter all four colors individually. Here are my questions: Is there a way to save/use the existing calibration curve as my new current curve? If so, I then plan on creating a new, CMYK curves, target curve which according to the users manual should work, any thoughts on this process?

A note about Harmony curve naming:

A target curve represents the tonal or dot gain characteristic of the printing that you want to match.

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

A derived calibration curve is what Harmony creates from your desired printing tonal or dot gain target and current tonal value or dot gain characteristic of your printing.

In short: Target curve is what you want, Current curve is what you're getting, and Calibration curve is what Harmony will create.

Target and Current are presswork curves - not plate curves.
Calibration curves is the curve that will be applied to the plate.

Unless you are in an unusual situation there is no need to linearize your plates before creating curves (G7 or otherwise). There is a longish explanation as to why this is so here: The Print Guide: To linearize your CtP plates or not?

You do need to make sure that your platesetter images consistently.
You do need to make sure that your press is printing reliably and consistently otherwise your curves (G7 or otherwise) will cause problems.

Have you run any press tests to make sure that there are no inherent press issues?

Why are you wanting to be G7 certified?

best, gordo

 

[Angie]

Hi Gordo-
I do understand the differences in the curve names. When our Prinergy system was installed in 2008 these curves were created to make sure any tonal value in the file was accurately reproduced on the plate. Ask the Kodak installers why.

The platesetter is imaging consistently. We have a PM done every 6 months and the exposure is tested and adjusted if needed.

As far as the press and the printing is concerned you have been in the business long enough to know if there were problems prepress would be the first to hear about it

Test sheets done when Prinergy install happened. No further testing. Production manager wants to run the first iteration of the certification process exactly how we run our jobs and adjust from there. Which is why the question is can I extract the data from the calibration curve from Harmony to use as my current curve.

Why G7 certified? Good question. The real answer to that is our GM thinks it would be a great "feather in our cap" never mind the pain and anguish it causes the production people. I get paid to do a job and keep my mouth shut so can I extract that data or am I starting from scratch?

Frustrated in WI

 

[gordo]

Hi Gordo-
I do understand the differences in the curve names. When our Prinergy system was installed in 2008 these curves were created to make sure any tonal value in the file was accurately reproduced on the plate. Ask the Kodak installers why.

In my experience the installers were following your managers instructions - without question. That was (and probably still is) a big problem.

Test sheets done when Prinergy install happened. No further testing. Production manager wants to run the first iteration of the certification process exactly how we run our jobs and adjust from there. Which is why the question is can I extract the data from the calibration curve from Harmony to use as my current curve.

You could, but I think that it will just cause confusion.

Why G7 certified? Good question. The real answer to that is our GM thinks it would be a great "feather in our cap" never mind the pain and anguish it causes the production people. I get paid to do a job and keep my mouth shut so can I extract that data or am I starting from scratch?

Tell your manager that (s)he's an idiot. Hmm maybe that would cause more problems. ;-/

In your case, I would start from scratch. Go through the whole process (and expense) - after all that's what your GM has ordained. Don't do a patch job or try to cut corners. Just do what it takes to do a G7 implementation starting with a prepress/press audit based on press tests. I.e. After all it's going to cost time and money to do it right or why bother.

best, gordo

 

[Angie]

Well, we got our certification!!! Now even more fun coming my way. Is there a way in Prinergy 5.1.2.3.8 to apply one of the colors of my CMYK curves we created in the certification process to a spot color for 2 color (K + PMS) work? We do not use %AUTO% in our process template since it is not a good fit for our workflow. I have a bad feeling I may have to build a spot curve in Harmony and output the spot plates separately from the K plates. I am hoping one of you fellow printers out there will tell me this is not so. Keeping my fingers crossed in WI

 

[Kaoticor]

Can't just output your spot color plate as a cyan plate, magenta plate, etc...?

 

[Angie]

We worked very long and hard with this customer to get them to build their files using the appropriate Pantone swatch plus there are graphics involved so I would hate to take a risk that they would come out incorrectly. I feel it is a safer bet to apply the CMY curve to the Pantone plate if possible.

 

[Bill W]

You can control the angle of spot color screens in the Calibration & Screening area of the process template by selecting which color to map to in the Default Spot Color Handling area. However it appears that regardless of what color you pick, the curve value for that color, if it is a tint, will match to the K curve in the Harmony curve you select in Print Curve Calibration.

That said, my experience is that one "almost always" picks the K curve for spot color tints. If this is the route you want to take, you could use your "G7" curve and then select what angle you want the spot color tint to be so it does not moire if the black in your two color mix is screened.

 

[danremaley]

Hi Angie, I feel your 'pain' with the G-7 stuff. I was at GATF when Don H. developed it. It requires you to run more Magenta (not a good thing) and more Cyan to compensate for the "Magenta cast". I recommend printing lower densities 1.30 Cyan 1.40 Magenta, you'll be a little off the "Delta value" for solids but you'll be more successful at press, giving them a wider latitude. I have the tone scale values for the "wanted" measurements for standard commercial printing, If needed.
Dan Remaley