Grey Balance

[PeterA]

I am still trying to get to grips with this

In Europe the majority of our proofing uses the Fogra39 profile - so the paper is made to look like b -3 its puts ayellow tint in the background of my proof paper as it is too blue.

When we print on any commercial paper it has a b -5 so it is bluer. We now adjust the cyan and yellow in to match the (less blue of) the proof paper. So when comparing it with the 50% Black patch it now looks a little yellow.

Is that what happens when you try to match the G7 proofs

Peter

[Colorblind]

Chances are it puts that yellowish background tint because your rendering intent is "absolute colorimetric". Try "relative colorimetric" and see if it gives better result for matching your bluer stock. Your 50% black shouldn't have a yellow cast anymore. Also you may need to tweek your proofer profile a bit to get the perfect paper background color when using "absolute colorimetric".

Hope this helps.

[JRom]

Its putting yelo in to counter the effect of the UV brighteners in the paper.

High -B* in your paper white is an indication of UV Brighteners.

A G7 Certified proof will not exhibit this problem as the ISO spec is requiring a L*95 A * 0 B* -2

Go to the Gracol site and download the how too......its FREE !

Also the Fogra and G7 characterization data display almost Identical white points.

John

Edited by: John Romano on Jan 24, 2008 9:45 AM

[PeterA]

John

Not quite off subject - If you print for magazines with adverts in - do your advertisers have to send in certified proofs that you have to match to.

Peter

[JRom]

We don't do Magazine printing but I would say yes they need
to supply a certified proof and we would have to match it.