EFI vs. GMG vs. CGS...is there a clear winner?

[meddington]

Now, why am I saying proofing papers should be free of OBAs, as some people say, hey I have it in my press stock too, so it should be the same. The reason is, it never behaves the same,

"Never" might be a bit presumptuous. Moderate amounts of brighteners between papers *can* behave similarly, and *possibly* yield a closer visual result than having one paper OBA free. A good argument for OBA free is that it is not excited by differing amounts of UV in the lighting conditions. This usually doesn't hold true for the press stock though, which almost invariably contains OBAs. Suffice to say that its possible to find a proof paper with moderate amounts of OBAs that work well in a particular lighting condition with a particular press stock.

and most users, at least in commercial printing, will not put their spectrophotometer on printed stock any more. Why should they? To do what? Fingerprint a press?

This is as much visual as measurable, but how about to more closely align the proofing simulation to the actual press substrate?

We finally have printing standards in the market and people have come to grabs with them. In Europe, the universal language is ISOcoated V2, and this is what most of the proofs relate to. So as long as I have set up my proofing system to be able to print the different color spaces and paper categories, and all Rip vendors supply these profiles for their systems, there is no reason to create your own profiles,

I'm certainly all for standardized printing and proofing, but I do find it beneficial, and often necessary to augment the white point of the proof to match the final press substrate. Differences in paper shade can have a significant effect in highlight tones and affect visual perception. For example, if I provide proofs toward SWOPcoated3, which has essentially a white point of a*=0, b*=0, but the press stock measures a*=0, b*-5, there's likely going to be a visual difference that can lead to issues on press.

but you need to recalibrate your system every once in a while, and there you measure on the proofing paper, and OBAs will get in the way and throw off your measurements. The other factor is that inkjet proofs on paper containing OBAs will rapidly degrade, and this is very well an absolute no no, for instance in catalog production which may last a few weeks. This is also the reason Fogra will only certify papers with no or very little OBAs, as others will fail the aging test.

"Rapidly" can be a relative term. I've got proof samples on paper with a fair amount of OBAs (b*=-5) from few months to several years back that measure identically (for all practical purposes) as they did when they were first produced. Of course I agree that OBAs can degrade, but how proofs are stored can make a difference.

 

[Ian Mackenzie]

Heiner -

My data comes from others who are much smarter.....like paper mills. These are not subjective opinions that I invent.
So, in the interest of staying consistent, please allow me to quote something that I received at my office just yesterday.

(Article written by Dr. Martin Habekost - assistant professor at the School of Graphic Communications at Ryerson University in Toronto. He received his PhD from the University of Hanover in Germany.)

IPA Bulletin: September/October 2009

Headline:

"Optical Brighteners: Friend or Foe?
Although some of the process colors will be affected by optical brighteners, it is possible to still get good color reproduction through color management and ICC profiling"

"The Challenge Continues"

"Optical brighteners are used in many printing and proofing stocls to achieve a more eye-pleasing and crisp-looking white sheet. Papers containing OBAs are more and more the norm and it is hard to find printing paper that has no OBAs in it.

Since OBAs can distort the color reproduction of some of the process colors (C and Y) it is necessary to use the help of ICC-profiling to compensate for the effect of OBAs. Although there has been a compensation module available in the popular ProfileMaker software, X-Rite has come up with an empirical solution that works through a special gray balance compensation. It needs to be seen how successful this solution is.

A definite answer to this challenge still has to be found. It was encouraging to see proofs that provide a good visual match to a printed or proofed standard and that the visual match was done at a customer's site using software that is avaialble in today's market."

So I guess it comes down to a simple cost benefit analysis that needs to weigh OBA-free paper against paper with trace amounts of OBAs that may require some profiling. As far as i know, most color management today requires profiling.

The costs are easy to calculate. Let's say a print provider or premedia compnay uses five 42" x 98' rolls of a 250 gsm satin or semi-matte paper. Their choices may be:

1. CGS pearlproof - sells for $1.19 per sq. ft. ($408 for a 98' roll. Yes, I know that CGS sells 150' rolls)
2. GMG - sells for $1.39 per sq. ft. or $479.00/roll
3. Validation Media - sells for $.72 per sq. ft. or $249.00 roll
4. Epson - sells for $.69 per sq. ft. or $239.00 roll

So, let's quantify the costs per month:

1. CGS = $2040/mo.
2. GMG = $2395/mo
3. Validation Media = $1245/mo
4. Epson = $1195/mo.

One can then easily measure the financial metrics of the OBA debate and decide what they want to do in the context of the diverse opinions stated here. Good results will be achieved using any of this paper driven by any RIP from CGS, GMG and EFI.

Again....."is there a clear winner?"
My opinion is no.

Best,
Ian

 

[Mike Strickler]

OBAs

OBAs

I'll just weigh in briefly in this. As far as I know--and perhaps a paper manufacturing expert can speak more to this--it is impossible to produce a bright white paper, say 95 L* or above, with consistent color, without employing at least some optical brighteners in the coating. This is why most or all responsible paper vendors admit to at least small amounts of OBAs in such papers. This is important because one cannot make an accurate proof where the reference press substrate is brighter than the proofing paper. It's worse than that: If the press stock has the same L* value as the proof paper but is, say, bluer, which is extremely common, even the dominant reality today, the addition of cyan and magenta dot used in the background of the proof to match the hue to the press sheet color will darken the proof, sometimes to the point that it's completely useless. In that case one needs a proof paper that is even brighter, in which case, again, OBAs come into play. If you are proofing for publication, especially a #3 paper or darker, this is not a problem, and there are many OBA-free proofing papers available for this purpose. The workaround is to use one of the coated press papers that Mike has mentioned, but there again, this will inevitably mean using a paper that has OBAs, and likely in far higher amounts than one will encounter in a dedicated proofing paper.

 

[edwinb]

I support Rips technically and based on the latest current versions (gmg/Efi) I pick EFi as quick, fast, very accurate profiles, Spot colours from the full range of the printer and better integration with x900 epson technology.

I think the comment about Epson picking EFi is spot on - I'm sure they did there own tests first befor committing themselves to a partnership

But I am happy to support/reprofile any of them and also advise on the available 'drop in' replacement papers for the expensive proprietry papers like gmg 250 without reprofiling.

Edwin

 

[schenkadere]

I support Rips technically and based on the latest current versions (gmg/Efi) I pick EFi as quick, fast, very accurate profiles, Spot colours from the full range of the printer and better integration with x900 epson technology.

I think the comment about Epson picking EFi is spot on - I'm sure they did there own tests first befor committing themselves to a partnership

But I am happy to support/reprofile any of them and also advise on the available 'drop in' replacement papers for the expensive proprietry papers like gmg 250 without reprofiling.

Edwin

I appreciated a committed response. Thank you.

 

[jari716]

EFI4.01 is better than EFI3.1.8,so you can update it,The Gray balance is ok.GMG and CGE have the same technique a principle.

 

[schenkadere]

EFI 4.0.1 is much better than 3.1.8...I'm very happy now.