press calibration

[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]

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]

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?