press calibration

[Tahir]

hi can any body help me ,to tell me about the whole proceeder of press calibration & how can i produce press profile to print as per my proofs, Thanks in advance.

 

[Lukas Engqvist]

If you search the threads this should a similar question has been discussed.

Normally though you would make your press print to a standard, G7 or fogra's interpretations of ISO 12647
Then you would make your proof match the same standards profile. And verify your print.

these are some of them:
http://printplanet.com/forums/color-management/20210-color-management-what-really
http://printplanet.com/forums/color-management/15139-press-calibration

 

[TerryWyse]

hi can any body help me ,to tell me about the whole proceeder of press calibration & how can i produce press profile to print as per my proofs, Thanks in advance.

How much time you got??



Terry

 

[Tahir]

actually i want the to know the method step by step ,including printing patches , measuring them to see the tvi etc & all parameter , calibrate the curve put the reading into soft where to create a profile for the press.I need to know the method step by step & also want the soft where names which can be used for profile making & how can i measure the patches x rite name which one or another one please help me to create a good profile for my press . Thanks again to listen me . by

 

[Lukas Engqvist]

There are several methods to do this. But this as many other skills is what some people specialise at, I have not seen a manual that goes through the steps. I am part of a network of printers, and wrote an internal manual to deal with this, but it was in Swedish. Compiling the knowledge and experience we have into a step by step guilde is a tedious and time consuming task. (If I had written such a book, I'd probably have to charge for it too). I would advise to get a consultant to walk you through it the first time. Maintaininig a press/prepress system in tune is still a job that needs to be done, but having a consultant taking you step by step in your own workshop is still a good place to start. Where is it you are working? Have you thought about if there is a regional standard? Are there other printers that you can collaborate with to get a better understanding? Perhapps going to visit a site where you know they have made the journey?

I am sorry to have to bounce back with so many questions. But I think some of us almost read into it the same kind of open ended questions as "could tell me everything about french?" There is plenty information but hard to find the right information in an easy to read format.
To answer specific issues or clarify what you don't understand is easier.

The principles are:
Getting down all your variables, so that you have a stable environment and documenting them.
Then you need to decide what standard you want to target.
You may have to change your variables so that the target is reachable. (the colours of your primaries and secondaries, solid density etc and decide on other variables like screening )

Once all is stable make an adjustment so that you can match the tone curve.

Then the next (optional) stage would be to maka a profile specific to that status, (see threads on fingerprinting).

Your proofer would then undergo a similar process.

 

[prepressing]

The steps vary depending on the type of RIP or Workflow you are using. They also vary because you have to properly adjust exposure and calibrate each device that is used before getting to the press. In other words you first have to calibrate your platesetter. Once this is done then you can calibrate your press. Once that is done then you can output a calibration test to the platesetter and make sure it is correct. After the platesetter has been calibrated you can start calibrating the press using press targets output from your RIP or workflow.

 

[Printservedigital]

£60 and Hour and I can help LOL

 

[martin.weberg]

Based on your first question I recommend you to hire a consultant. Many things might go wrong and when it does you need to be able to analyse it.

 

[Printservedigital]

My Rates are negotiable.

 

[Kido]

To calibrate our press we bought GMG-software; PrintControl and RapidCheck.
Our set-up contained following steps...
1. Linear Compensation
At first, it's very important to expose the nominal value.
Any platesetter has a handicap. For example, a digital 50% will be exposed as 48%.
So you have to execute a compensation in RIP, by which the 50% actually will be exposed as 50%.
Make a fingerprint with different densities on the inkzones.

2. Dot Gain Compensation (DGC)
Dependent of the standard you want to reach, find the optimal density.
The optimal density will develop the desired Lab-value; defined by the standard (e.g. ISO 12647-2).
By using PrintControl, compensation-curves will be created. Develop plates with the linear- AND DGC - curve and print it.

3. Fine Tuning
Adjust the curves to match the proof, based on the standard-profile in the proofer-software.


PrintControl is a very useful application because it's wizard-based.
RapidCheck will be used to verify the desired parameters and adjust them if necessary



Grtz

 

[gordo]

To calibrate our press we bought GMG-software; PrintControl and RapidCheck.
Our set-up contained following steps...
1. Linear Compensation
At first, it's very important to expose the nominal value.
Any platesetter has a handicap. For example, a digital 50% will be exposed as 48%.
So you have to execute a compensation in RIP, by which the 50% actually will be exposed as 50%.
Make a fingerprint with different densities on the inkzones.

That step is not required. It doen't matter whether a 50% reads 50% or whether it reads 48% as long as it consistently delivers the same %.

best, gordon p

 

[Tahir]

thank you kido ,now would you like to tell me how you measured the printed test chart i mean by which ? x rite etc or GMG & please let me know the web site of GMG thank you very much again & the rest of my all fellows for thier effort .

 

[printnewb]

Can-o-worms

Can-o-worms

hi can any body help me ,to tell me about the whole proceeder of press calibration & how can i produce press profile to print as per my proofs, Thanks in advance.

Tahir,
Can you provide more detail on what you print? Are you talking about 4 color process work? or just simple halftone calibration?
If it's simple press calibration, just create a page with screens from 1% to 99%, maybe in 10% increments, then print them on your press. Measure the results with a reflective densitometer then use those values in your RIP's linearization curves.

Note: Typically when you do a linear calibration on the press, your jobs will look lighter than you're used to because there is normally an expected dot gain for your press.

For the second part of your question about proofing is a whole new "can-o-worms".

Printnewb

 

[Tahir]

we are producing catalogues ,magazines & flyers etc . Some time colors dosent match

 

[disbellj]

This reply does not take into account that primaries and overprint secondaries must be within 5 Delta E tolerance of solids for ISO12647-2 to be adhered to. So a spectro is needed for that, is it not? After that, then G7 How-To says to correct for the NPDC, or Neutral Print Density Curve. First solids, then dot gain if needed (now called TVI) to correct for tone curve and gray balance. That is, unless I'm misunderstanding the way things are supposed to be done these days. Let me know.

Regards,

Don

Tahir,
Can you provide more detail on what you print? Are you talking about 4 color process work? or just simple halftone calibration?
If it's simple press calibration, just create a page with screens from 1% to 99%, maybe in 10% increments, then print them on your press. Measure the results with a reflective densitometer then use those values in your RIP's linearization curves.

Note: Typically when you do a linear calibration on the press, your jobs will look lighter than you're used to because there is normally an expected dot gain for your press.

For the second part of your question about proofing is a whole new "can-o-worms".

Printnewb

 

[printnewb]

Yes, Don is correct. I described a simple approach to a complex issue. There should be a standards adhered to by your various printing methods. Simultaneous compliance with ISO12647-2 type 1 and SWOP should be used for publications and ISO12647-2 type 3 and GRACoL 7 for flyers/commercial printing.

Printnewb

 

[Kido]

thank you kido ,now would you like to tell me how you measured the printed test chart i mean by which ? x rite etc or GMG & please let me know the web site of GMG thank you very much again & the rest of my all fellows for thier effort .

Tahir, i'm sorry for my late reaction.

GMG-software (PrintControl & RapidCheck) with an additional EyeOne-spectro will do the job. It did with us so...

You can find more info on 'http://www.gmgcolor.com'.


Grtz

 

[turbotom1052]

i would start by making sure that the press is set up to manufacturers specs. be sure that all the grippers are set correctly and that the pressures are as per manufacturers specs. then make sure the press comes up to correct ink /water balance and work things from the press backwards into pre press

 

[Doug M]

wrinkled sheets

wrinkled sheets

Can anybody tell me how to get a 4 pt stock sheet to run on a topspot 102 with a cyrel plate without wrinkles running of the back of the voided areas?