Archive for the 'inkjet' Category

Virtual Proofing - Oh Boy!

Published
by
Jim Raffel
on April 17, 2008
in blogging, calibration, color, inkjet, measurement, monitors and proofing
. 1 Comment

I believe virtual proofing is at the same cross roads ink jet proofing was around 2001.  I am both hearing and observing information that provides growing support in my own mind for this position.  First, I am not going to name any names in this post.  Why?  Because gut feelings and intuition are not fact.

Think back to 2001 and earlier as it relates to ink jet proofing.  For a frame of reference think Print ‘01 in Chicago, just try not to remember that 9/11 fell right in the middle of the show :(   We finally had a good stable pigment based printer.  We had a few good RIPs emerging from the pack, but you still really needed 3rd party color management software to make the whole thing work.  Of course there was the nightmare of the day which was trying to find a suitable media for Graphic Arts proofing purposes.

The reality was if you understood all the steps involved (or hired a good color management consultant) you could make decent ink jet proofs that rivaled the standard analog and digital proofs of the day.

Now think about virtual proofing today.  While I believe there are at least two (and quite likely more) solid products capable of producing virtual proofs rivaling the ink jet proofs now carrying the standards flag; getting even those two systems to work in multiple locations can and does prove tricky at best.  This is no knock on the virtual proofing software vendors, but instead really an issue of hardware.

Putting together a solid ink jet proofing system requires an end-user to source a printer, media, a RIP, a computer to run the RIP, and probably a good color management consultant as well.  Putting together a solid virtual proofing system requires sourcing a display…let’s stop right there.  There is more to it, but the display is proving (at least my gut tells me this) to be a huge thorn in the side of virtual proofing working in multiple locations.

I am hearing some crazy numbers like less than 1 in 10 “qualified” displays can be used in a 2 or more location virtual proofing set-up.  If this is true (and I am starting to think it is), than it is no wonder virtual proofing is being used more and more for intermediate color (as I predicted in a previous post) and good old reliable ink jet proofs are still being produced as a final contract proof.

I still believe virtual proofing will continue to make gains over hard copy proofing.  I just think it may be a little slower than we thought until this display issues gets worked out.  Part of the problem is that measuring displays is not the easiest thing in the world to do….but that could be a whole post or even a complete white paper.

#29: Inkjet proofing on the exact paper you print on

Published
by
Jim Raffel
on March 29, 2006
in Print 05, inkjet, paper and proofing
. 0 Comments

During Print ’05 in Chicago ColorMetrix shared a booth with AbsoluteProof, who also invited Pierre Ferland from The Whole Proof. The Whole Proof has developed an innovative new technology which allows virtually any printing paper to be specially coated and then utilized on an inkjet printer for proofing purposes. In last week’s Golden Nugget I discussed the importance of gloss being the same for two printed samples to appear the same. What I found interesting when I requested “bullet points” from Pierre to prepare this week’s e-mail is that he addressed gloss better than I could have while explaining the importance of his product. So, the rest of this week’s e-mail is provided by >Pierre Ferland of The Whole Proof (pierre@twproof.com)

For the cup manufacturer’s story: They were proofing on Epson matte heavyweight paper, but the characteristics of that paper were not consistent with what they were using on the press. The branded inkjet paper was much brighter and smoother than the food grade SBS that they were printing on. When they tried to emulate the SBS’s brightness using the plotter’s ink, it made the paper glossy (typical with pigment-based inks). Even if that hadn’t been the case, very smooth paper reflects light more directly than “fuzzy” paper, which diffuses light. The print buyer and pressman were getting proofs that were much more vibrant than what could actually be accomplished on the “beverage cup” SBS using a flexographic press. Proofing on the same paper they use on the press not only gives their pressman a more realistic target, but it also allows them to set the right expectations with the print buyer, and supply fully functional, full color prototypes made from the actual press stock the whole proof, and nothing but the proof! - Pierre Ferland (TWP International)

Coming next…Jim Raffel’s thoughts on GRACoL 7

#28: The difference between satin-gloss & high-gloss

Published
by
Jim Raffel
on March 21, 2006
in gloss, inkjet, paper and proofing
. 0 Comments

– FREE pass to Monday Night Expo and Paper Show at Print Oasis: ColorMetrix will be exhibiting at Print Oasis (April 2-5Las Vegas) a www.printbuyersonline.com show. The ticket at the link below will get you into the Monday night Expo for FREE.

http://www.colormetrix.com/docs/Paper_Show_Ticket.pdf

*** Golden Nugget #28: The difference between satin-gloss & high-gloss ***

…Everyone has an idea of what the terms “glossy” and “matte” mean. In case of terms like “satin-gloss”, “high-gloss” or “satin-matte”, however, which are often used in the printing industry, different observers may reach different conclusions… (Source: http://www.qipglossmeters.com/glossmeters )

For many years ColorMetrix has quietly developed keyboard wedge software for a line of gloss meters manufactured by Quality Imaging Products. As a result I have had the opportunity to test and work with the Gloss Meters and have also developed a pretty good understanding of why one would want to measure gloss in the printing industry (even though very few of us do).

In the last few weeks I have been assisting clients in understanding why their inkjet proofs do not match press sheets even though they have gone through the entire color management process. The problem in more than one case has been the inkjet paper selection. For sake of argument, we are printing on a semi matte sheet and proofing on a semi-matte inkjet proofing paper. Even if both the inkjet proofing device and the press have been profiled, these two papers are not the same and probably do not have exactly the same gloss. While a paper simulation is nice, it does not adjust for the difference in paper coating which is best quantified by gloss measurement.

Gloss has a great deal to do with how our eye and measuring instruments see images printed on paper. If for some reason you do not believe this, compare an identical advertisement printed in a newspaper versus weekly news magazine.

If anyone would like this quantified, please feel free to send me samples of your proofing paper and the papers you are using this sample to represent. I would be happy to measure the gloss of both and get the results to you.

Coming next…Inkjet proofing on the exact paper you print on.

#27: Measuring TVI on Inkjet proofs is Meaningless

Published
by
Jim Raffel
on March 9, 2006
in TVI (Dot Gain), density and inkjet
. 0 Comments

Part 5: I should start by saying I have covered the topic of using graphic arts densitometry to evaluate inkjet proofs once before. Back in July ’05 GN#5 addressed this same issue so you may wish to refer back to it. I considered changing this topic, because the title is a bit inflammatory. Understand that my frame of reference is users of our software who rely upon density and TVI as process control measurements for inkjet proof production.

Far too many times I have seen the density and TVI values stay within tolerance, and yet the Delta E shifts can be huge. Those of you who follow the blogging I do at JimRaffel.com (yes, I write more than once a week sometimes), saw a graph of the spectral response of the Red, Green, Blue, and Visual filters used in graphic arts densitometry. Those filter responses are specifically designed to address the spectral response of process cyan, magenta, yellow and black. While I was not able to find them for this week, I have seen graphs which compare the spectral response of offset printing inks with typical inkjet inks. By next week I will either find the curves or reproduce them myself once I am back in the office. A picture will be worth a thousand words when I post those graphs at JimRaffel.com.

Coming next… How important is Gloss?

Golden Nugget #7…Ink Jet Proofing Dry Time Prior to Measurement

Published
by
Jim Raffel
on July 27, 2005
in inkjet, measurement and proofing
. 0 Comments

*** User’s Group Conference News ***

Even though the date to receive our guaranteed pricing on rooms at the Mirage has passed it is not too late to attend the 2005 user’s group conference. If you are still interested in attending, we may be able to assist attendees in getting our hotel rates ($129/night for Sun, Mon, Tue, and only $199 for Sat. night!) Complete conference information can be found at (http://www.colormetrix.com/cmug05/). Before calling the hotel for a room, please give us a call to see if we can assist you with a room at the guaranteed conference rates.

*** Jim Raffel’s Week 7 Golden Nugget…How long do I have to let my ink jet proof dry before I measure it? ***

While there is not single correct answer to the question above, we have some basic guidelines from the field. Obviously, before following our suggestions it is very important to check with the manufacturer of the paper and ink that you are utilizing to print your proofs. They should know how long a dwell time is necessary before the proof is sufficiently dry that no more color shifting is occurring.

So, our general rule of thumb when we go in the field and assist our customers in setting a baseline or gold standard is to wait 30 minutes after the proof has finished printing before measuring it. We vary this a bit depending on the ink technology, pigment vs dye, but it seems to be a pretty good rule of thumb.

Now, we recognize that waiting 30 minutes to measure every proof may not be practical, but we are talking about the baseline or gold standard proofs right now. Once you have that down, it’s time to make another proof, to test for the optimum dry time for measurement of production proofs. Starting five minutes after the proof has finished printing measure the control strip every 5 minutes for half an hour.

Using the software you utilized to measure the proof take a look at the trend line analysis of the Delta E shift over the 30 minutes. You should be able to see a clear place where the shift levels off. Again, depending upon your environment (temperature and humidity), and proof type (pigment vs. dye) this could be at 10 minutes or 20 minutes.

That’s it! You now know how long to wait in order to get accurate proof verification measurements. If by any chance you are having trouble getting the trend line analysis I mentioned above out of your software….I know a great little software company called ColorMetrix that will be able to assist you in fixing that problem!