Goodmorning Michael.
I am a colour printer in the UK.
You have a few options
and it really depends how much this cliient spends and whether they are
right or you are.
The options you have are
(1) Match their proof on the press
(2) Persuade them of the errors of their ways. and you are right.
The first thing I would look at is how I am printing - regardless of screen
(ie 150, 175,200 stoachastic) the digital dot value on your sheet should be
( + or - 4% ) 10 =14 20 = 27 30 = 41 40 =53 50 =64 60 =74 70= =83 80 = 90
90 =96
the Lab colour measured dry with black backing on 115gsm gloss should
be
C 55 -35 -51 M 48 73 -5 Y 87 -4 92 K 16 0 -1 Varience is
DeltaE 5 (ISO 12647 2)
THese setting will give match the latest Pantone Colourbridge CMYK
colours
The Second thing I would do is set my proofer up - not to match my presses
but to match the standard ( in my case it is ISO Coated) it may be SWOP in your
case .
You should be matching presses to proof (not other wat
around)
One easy way to check your press is to check the grey balance ie 50% black
= 50%C 40%M 40%Y - if you havent this on your colour bars then print two patchs
- they should match and the CMY patch should be neutral.
THis is an important test of a press as nuetrals greys made up of CMY in
halftones always catch us out
Once you have acheived this - then my agument to the client is - we
match Pantone CMY colours and also those greys in CMYK haltones, to change what
we do would cause us a lot of problems.
All the best
Peter
I have just gone through my press room and we are now matching ISO Coated
proofs using Creo's Stacatto and clients love it