Archive for the 'measurement' Category

Virtual Proofing - Oh Boy!

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.

#68: Sustainable Green Printing

What is this new and latest buzzword sustainability? If I have offended you by calling it a buzzword I am not apologizing. Please do not misunderstand me; I think sustainability is a good thing. Smart printing businesses have been engaging in most if not all of the components of sustainability for years. The reason is quite simple - PROFIT.

Recycling is a key component to a sustainability program. Has anyone reading this been around long enough to remember the late Roger Dickeson’s War on Waste (WoW) waged by web printers back in the 70’s, 80’s and early 90’s? Did they do this to be “green” or “sustainable?” Personally I think not - they did it to MAKE MORE MONEY!

Did the web printer I worked for in the 80’s and 90’s commit more resources to better segregation of waste paper streams, including office paper, to be green or sustainable? Did we find ways to recycle even the cores from our rolls of web paper to be more sustainable? No, we did these things to reduce the cost of waste disposal and increase the revenue received for recyclable product. The net result of course was that we became more sustainable and green.

I suspect the sustainability ‘consultants’ out there are screaming right now that he does not get it! While you may be right, I do understand that there are other components to a complete sustainability program including a social responsibility component. I am sure even the social responsibility component of sustainability, when properly executed, can and will result in more of that dirty word - PROFIT.

What caught my interest about sustainability is that improvement must be measurable. Then I got to thinking - if the sustainability movement repackaged WoW, what else have they repackaged and re-labeled? Deming’s Statistical Process Control (SPC) that’s what. The past twelve years of selling and servicing ColorMetrix color verification and process control software has provided me with a good knowledgebase in this area. I have also written quite a bit about the topic on this blog.

Since you can read all the past posts, I will keep my explanation of using process control in a sustainability campaign short and sweet. Following is a simplified ink jet proofing example:

  1. Establish a baseline of ‘bad’ proofs as a percentage of the total produced.
  2. Utilize color verification and process control tools like ColorMetrix and ProofPass.com to verify color quality of all proofs produced.
  3. Review process control charts and other data to establish when and why variation/drift is occurring.
  4. Fix/Improve the causes which can be fixed and improved, and learn to ignore the special causes.
  5. Return to step one and compare current results with the baseline.

SPC works and Quality is NOT free, it is instead an investment with a return.

#67 Metamerism: Hard copy vs Monitor

The most visited post on JimRaffel.com in 2007 is #16 written October 2005 and addressing metamerism. Because of the popularity of this post I have decided to revisit the topic. I will start with some basic terminology and definitions. Then, I am going to present a real world example we are dealing with right now at ColorMetrix.

Definitions: First, metamerism requires a pair of objects. The two objects are often referred to as a metameric pair. In order to be considered metameric the pair must; match under at least one combination of illuminant and observer; not match under at least one combination of illuminant and observer; and have different spectral response curves.

Metramerism Tests: Post #16 shows an example of the GATF REHM indicator used for visual assessment of light sources. This is also an excellent of example of a visual test for metamerism. The two samples may also be measured by a spectrophotometer, and then an instrument test for metamerism can be performed. If the two samples exhibit a small Delta E under one illuminant observer combination, but have different spectral curves that cross at least three (3) times they are metameric.

Our ProofPass.com system was recently used to measure two samples. Below I have provided the L*C*h* values of a ‘Red’ swatch measured on a hard copy proof and then reproduced and measured on an LCD monitor.

  Hard copy Monitor
L* 40.56 43.02
C* 60.85 61.31
h* 28.44 27.9

The CMC(2:1) Delta E of the above two samples is 1.34 in a D50/2 degree environment.

Now, take a look at the spectral reflectance and emission curves of the two swatches. (Library Reading = Hard copy and Sample Reading = Monitor)

graph_spectralphp.png

Again the instrument test for metamerism states that if the spectral curves differ, and cross each other at least three times, then the objects are metameric. The curves look different and I count at least 10 crosses.

As long as the physical sample is viewed in a proper viewing booth, and the monitor continues to be calibrated and also viewed in proper conditions, the metamerism effects of hard copy vs. monitor proofing above should not be a problem. My concerns about this type of metamerism extend to placing a package on a retail shelf which is seldom a D50/2 degree environment.

65-2: New Media vs. Old Media at a Trade Show

As a member of the new media I would like to thank the SGIA show management for their recognition of the shift that is occurring in the way people gather news and information. While JimRaffel.com is not listed among the 22 most popular blogs in the world we do a pretty good job reaching those interested in color measurement and process control. After a review of the site, SGIA show management was enlightened enough to grant me press credentials for the show.

What do new media writers have to offer a show like SGIA? When I planned my trip to SGIA I had two meetings planned as Jim Raffel, the CEO of ColorMetrix. Thus, I decided to make good use of my “spare” time at the show learning more about the specialty graphic market and sharing that knowledge with you, my readers. I think the key item that differentiates me from a traditional media writer is that I have no deadlines and no publisher demanding that I put out a specific number of words or posts each day, week, month, etc. I write only when there is sufficient copy to write about something, and by and large only as it relates to color measurement and color process control.

I do not visit the press room and pick up press releases. I observed most of the traditional media representatives picking up press releases at the press room. Then, they all make the rounds of the booths with the most compelling releases and speak with the marketing people there for the benefit of the company with the press release. I am not saying this is a bad thing, well maybe I am… We have a journalism graduate speaking to a marketing graduate, neither of which has probably ever worked an image in Photoshop, made a plate, run a press, etc… It is, however, a great way for those companies’ issuing press releases to get the information out.

Take a look at my previous post. Do you think the average trade magazine author in our industry could explain to you why Canon’s move back to an 8 color printer is significant? Would they understand that none of the RIP manufacturers could figure out how to properly render the RGB inks in the Canon’s 12 color printer? In this industry we just seem to do better with 8 color CMYK printers to render images. As a result it is difficult to hit a lot of the spot colors, but if the spot color looks great and the photograph of the kids eating the chips next to it looks awful, that is a problem.

If you do not believe me take a look at the redesigned Graphic Arts Monthly website and notice how prominent the blogs are. WhatTheyThink.com is another a good example of a new media site even if one does have to pay for the content that really matters. WhatTheyThink.com provided very significant coverage of GraphExpo (A printing industry trade show) all in digital form.

As for SGIA show coverage I had planned on more, but the Jim Raffel CEO guy got busy with many unplanned meetings. Many of my contacts from the more traditional side of graphic arts turned out at the SGIA show and are expressing a greater interest in bringing color measurement and color process control to the Specialty Graphic market.

#61: Get Over Your Measurement Fear

Fear lies clearly in the path of all roads to success. In order to succeed at anything in life one must first get past the fear associated with the task. Think back to the days when you were learning to throw and catch a baseball. Throwing was no real problem was it? No fear there. Now think about learning to catch the ball. Remember having to get over the fear of being hit by the ball? Remember the coach telling you to keep you body in front of the ball and never let the ball get by you even if it hits you and not the glove? Most of us have been hit by enough baseballs to know that it’s an irrational fear as it relates to succeeding as a baseball player at any skill level.

Measuring color with passion, persistence and pride as discussed in #60 is all about getting over your fear of the results. The first time someone brought up color measurement you probably thought “Oh no, what if the results are bad? What will we do then?” Once you started measuring, however, you realized that the numbers helped you solve many more problems than the numbers alone uncovered. (Look back at #60 and read about the air exchanger in the web pressroom.)

If you do not measure color you cannot control color. If you cannot control color you cannot increase productivity and profitability in every phase of your printing business. Assume for a moment that the above statement is true. So, by fearing color measurement, you really fear increased productivity and profitability! Does that even begin to make sense? No, fear of color measurement is as irrational as the fear of getting hit by a baseball while playing the game. I know you want to be a printer who operates in the profit leader category of the PIA/GATF ratios, so get over your fears of color measurement and start measuring color today.

#58: I Still Love the Smell of Ink in the Morning

I have been so immersed in virtual proofing over the last several posts, that I had almost forgotten how much I still love the smell of ink in the morning. Last week I had the privilege of spending two days assisting a customer in the set-up of our software primarily for use as a pressroom monitoring tool.

The experience reminded me of #55: Just Measure It! The customer is a web offset shop and has the same problem that most of our digital printing customers have (Oh, I love the smell of toner in the morning too!). The problem is that their press product is finished product and has no trim. Color bars are not an option on production work, and changing the design to incorporate color swatches would also be impractical at this time.

The solution turned out to be the same solution we employee with our digital printing customers. A test form is put on press twice a day and the results of those measurements are used to verify conformance to density standards across the web. A second control strip can be scanned to gather other print metrics like TVI, Print Contrast, etc.

The results in a sister shop have been improved consistency from day to day and the ability to monitor changes in density and TVI from morning (cold press) to afternoon (warm press). In a perfect world I would love to see color bars on every job, but we thought outside the box and found them a solution that allowed us to measure. Once they started measuring quality and consistency improved. Profitability and productivity are never far behind quality and consistency improvements.

I raise the challenge again…today start measuring something in your color workflow that you are not measuring today. Within seven days those measurements will point the direction you need to go to improve the quality and consistency of that process.

#54: Some Thoughts and Comments about Soft Proofing

In #53 I listed a bunch of color resources I had found on the web. I was looking because we are putting the finishing touches on the first beta release of our ProofPass.com soft proofing verification module. For me this project has turned out to be about the journey not the destination. Of course the destination which is a viable commercial release of the aforementioned product that we hope to make lots of money on is not a bad place to end up.

The Journey, however, has been like going back to school for a guy so grounded in the color science of the physical ink on paper side of our industry. I have come to the conclusion that a monitor is just another “black box” that creates color from my perspective. Just like a hard copy proofing system, a conventional printing press, or even a digital printing press is. So, that means if it can be measured it can be controlled.

The key to successful soft proofing appears to lie in the color management behind the system(s). I recently had the opportunity to view and measure eight displays powered by the soft proofing technology of three vendors all in one place. All were powered by Macs, but the displays came from two manufacturers. In our quick and dirty technology demo three of these systems (all under the control of one organization) came in with a very tight peak Delta E of only about 3 between the systems.

Monitors using the other vendors soft proofing technologies fell further out (as the software was pre-beta at that time I am going to omit any further numbers). The verification module did, however, catch that one of the monitors had been profiled to the wrong white point (let’s just say I was pretty pleased with the new toy we built!).

Surround lighting and viewing conditions will make any quality soft proofing system work or not work. I have read papers on subject, I have tested it myself, and I have spoken to people who have done extensive testing of the systems. The less surround lighting (other than your 5000K light booth) the better. The surround and viewing conditions should be identical to the ultimate conditions when you make your monitor profile. One of the biggest factors I have seen to making a good or bad monitor profile is surround lighting.

It is clear to me that monitor proofing is here to stay in our industry, and is also highly viable when properly utilized. While I do not see monitor proofing replacing hard copy proofing altogether, I do see it replacing hard copy proofing in some applications very quickly. In other areas I see monitor proofing replacing many of the internal proofing iterations prior to the hard copy “contract proof” used press side. Much of this is going to depend upon how tight the deadlines are for being able to change copy, and the perceived quality level of the work being produced.

#51: Proper Press Fingerprinting takes Commitment

In this installment we will address the third question Dale raised in #47. Dale’s first two questions got answered in #48 and #49 which can be reviewed at JimRaffel.com.

Now, onto Dale’s third question:

3. In fingerprinting our presses, we’ve run up against the dreaded “Hurry up and do it, but don’t put too much work into it.” What are your recommendations for impressing upon the higher ups that doing color balancing and working out the calibrations takes time?

I would suggest you have your management read JimRaffel.com. The reality, however, is that the culture required for completing successful fingerprints starts at the top and does not get worked up from the bottom. I spent the better part of the first ten years of my career trying like heck to change the culture of a printing company (now out of business I might add) from the echelons of lower and middle management. While I hesitate to use the words “It can’t be done” (and not because my Mom the English teacher told me to never use contractions), I believe this is one place where this expression applies.

I have been very fortunate in my career. At 21 years of age before I had even graduated from RIT I was able to observe one of the pressruns used to set the early SWOP press standards. A lot of very smart people participated in this run and the scientific procedure was impressive. Then, not a year later I was the guy doing all the print quality measurements on a brand new Baker-Perkins G14 that cost about 9 million dollars back in 1986. While I was just one member of a very large team, the owner of the company made it quite clear that he was not making his first lease payment until we had a press that was printing correctly.

Over the next 3 years I had the same responsibility as 2 more new presses started up in that facility. In both cases, the purchase contract was very clear that we did not make lease payments until the press met our print quality standards. While the company in general had an difficult culture, in the case of all three of these press startups the message from the very top of the organization was “Do whatever it takes to get a solid press fingerprint.” The reason was simple, without a solid benchmark at startup how could we ever know what condition the press was in later?

Dale, it takes a great deal of time, money and a great team to perform a successful and meaningful press fingerprint. During the press startups above, the fingerprinting process could go on for a week or more. The press was fully crewed and lots of paper was run during this time. All the support staff had to be available from pre-press, plating, maintenance, materials handling, and more. I don’t think it’s an understatement to say that these fingerprint cost $100,000 or more.

Now, not all fingerprints need to cost that much. I took part in a very successful fingerprint within the last 30-days that probably cost no more than about $10,000 including our software and professional services time. It is, however, a matter of scale. The client for the 10K fingerprint was simply making the first investment in end-to-end color process control. All the key players in this organization participated in the meetings and remained on-site during the 2 (14 plus hour) days required to complete the fingerprint.

The results on the second day (and in follow-up calls the last three weeks) continue to be impressive. In the case above the press is not brand new but instead a fairly old and well worn pieces of iron which is now printing at an impressive level.

My conclusion is simple. If senior management of a PRINTING company is not willing to invest the time money and effort necessary to perform a proper PRESS fingerprint, one must really question the value of performing the fingerprint.

#48: Make Proofs That Match Your Press

Since #45 in December we have been discussing resolutions to improve the quality of your proofs. In order to gain the full benefit of this installment one should have read and implemented the suggestions in #46 & #47.

Proceeding forward it does not matter if you are utilizing a methodology like GRACoL G7, or a more traditional color management approach. In either case you will include a target on each print job with the same color bar swatches that you output on the proof (#46). This will allow you to measure the press ok sheets and compare them to the proofs, thus building even a larger statistical database to call upon.

When utilizing software like our ColorMetrix and ProofPass.com products for process control and print certification purposes it does not matter if you are using a methodology like G7 or traditional color management. While there are some new formulas out there to run the collected data through the tried and true colorimetric data (L*a*b* and derivatives along with some version of Delta E), do a great job comparing two similar or dissimilar imaging systems.

Unlike density and dot gain values which must be used with pigment sets designed for 4/color process printing, L*a*b* values allow the comparison of an inkjet proof and an offset press sheet. This is possible because we are looking at the actual colors, not values derived from a formula which assumes a certain pigment set.

Not only will you be comparing the measurements of the proof to the press sheet, but you will be building a history of what is a “normal” print condition of each press and paper combination. Some refer to this as finding the “sweet spot” of the printing press.

Overall, as your volume of collected data grows you will be able to refine the system in small steps by reviewing the proofing and press information both independently and together. Using numeric results, charts, and graphs you will be able to see small differences in color that can be adjusted for over time. No system is stable over time, so continuous monitoring is a must in order to maintain stable color.

#37: Monitoring Digital Presses

At ColorMetrix we have some new and potential new customers who will be using our products (both ColorMetrix and ProofPass.com) to monitor and control digital presses like the HP Indigo, Xerox 8000, and NexPress. During our sales presentations most of these folks have expressed concern that the device is constantly self calibrating and correcting itself, so why would I need to do external process control?

My short answer: “Do you really want to let the fox watch the hen house?”

For the most part the internal controls on digital presses are built to keep the device in calibration. While these devices are different than conventional printing presses, they are not so different that we conventional printers do not understand them. There is a certain amount of variation that a conventional press self adjusts for like automatic register controls and the like. So, if we follow this augment to a logical conclusion that would mean process control would be useless on a conventional press as well. If you are reading this article I am fairly certain you do not believe that.

In general the act of process control requires the user to view the device (press in our case) as a black box. By measuring the resulting print the device produces, we are taking into account everything that happens in the device and the environment the device is in.

For example, several of these devices “self-calibrate” by imaging on a drum or a belt between actual substrate impressions. It seems to me we have removed a pretty important piece of the quality puzzle from that equation. What if our substrate is stored in a warehouse with no air conditioning and our press is in a climate controlled room? A week or so ago it was almost 100 degrees with very high humidity in the mid-west. If we bring that paper from the warehouse into the production room and do not provide 24 hours for the paper to acclimate, do you think we would get the same print result as we would with paper that had been acclimated?

If you said NO, please call me for a free trial version of ColorMetrix or ProofPass.com so you can measure it yourself.

In conclusion, all the variables that contribute to a printed piece like; faulty RIPs, toner changes, device wear and tear, paper changes, etc are viewed by a process control system like ColorMetrix as a black box. Process control systems like ColorMetrix measure the finished piece in order to accomplish two goals:

  1. Confirm that the finished print quality is within acceptable quality guidelines
  2. Provide detailed enough information to track back the problem portion of the process when #1 above is not achieved

Overall, the goal of the manufactures self-calibration procedure to stability of the imaging process itself. The goal of a system like ColorMetrix is overall print and color quality of the printed piece you put in the hands of your customer.