Archive for August, 2005

‘05 User’s Group Wrap Up

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Jim Raffel
on August 25, 2005
in GRACoL and blogging
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Well, I did not achieve my goal of a blog post everyday. With all the customers and other trading partners as well as the normal Las Vegas distractions it proved to be an impossible task. So, this post will cover the highlights of our Tuesday morning session:

  • We spent about half the morning discussing and showing how to create reference values and tolerance ranges to be used with primarily ColorMetrix. There are a variety of options, and I expressed my overall preference for a greater reliance on process capabilities. This is because proper use of process capabilities will lead to higher quality output at an overall lower cost. Obviously customer specifications can’t be ignored, but instead a way should be found to make sure that customer specifications falls within the process capabilities.
  • The balance of the morning was spent on reviewing best practices for press finger printing. From my point of view this was a great session, because of all the user input from the room. Many felt the highlight was reviewing a method of press characterization utilizing grey balance numbers measured with a simple densitometer, and our retired GATF Hexagon software. This technique worked 6 years ago, and now looks similar to what GRACoL is proposing.
  • Check my links section to the right on this page. There are many good resources represented. I utilized many of these links to prepare for the User’s Group Conference.

In closing, a good time was had by all. Our plans at this point are to return to the Mirage is late September or early October next year for our 6th annual User’s Group Conference. Based upon user comments and busy schedules we will be compressing the meeting to a shorter format.

I extend a personal thank you to all who took time out of very busy schedules to attend.

2005 User’s Group Update

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Jim Raffel
on August 22, 2005
in blogging
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I will start by saying too much has happened in the last day and a half to write about in a blog entry, so I will stick to the highlights here.

  • Mirage is a much nicer place to host a meeting than TI. The meeting rooms we have are awesome, and the food and food service personal are top notch.
  • Jerry Huffman provide an excellent keynote address last night. He shared AbsoluteProof’s overall success with GcX, and specifially success with EMI.
  • The Sunday night reception was once again a excellent networking opportunity, and a big hit with all attendees
  • Today (Monday) was a long a content filled day, and it has been every year. (It probably would have seemed to be a shorter day if my wife and assistant (Terra) had not “made” me stay out until 1:00am. )
  • Michael Woods and I presented a start to finish tutorial on using GcX. Without Son Do’s “questions” it would have been a boring session…
  • Jerry Huffman provided a detailed review of how GcX has been a piece of the enabling technology that allow them to sell sub-$5000 remote proofing solutions.
  • Howard Nelson (ASH) provided insight into evaluation of the Box Plot utilized in GcX for process control. He also provided a hands on tutorial and some sample excel sheets that allow in depth analysis of data collected by GcX.
  • I shared some more in depth perspective on the two Golden Nugget topics the group asked for more information on; density & TVI vs. L*a*b*; and UV vs non-UV filtered instruments. (I learned something here when a potential client shared some data with me….I may be crossing back over to the other camp depending upon follow-up on this information. )
  • The best part of any User’s Group is when the User’s share. Jeff Ross from Bemis shared real world experience with GcX. David Piccus also told us what happens in shops he helps who have no process control.

More to come tomorrow.

User’s Group 2005 T-minus approx 6 hours

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Jim Raffel
on August 21, 2005
in blogging
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Even with the delayed flight we made it to Vegas. Here we are out last night. Terra is on the left Michael Woods girlfriend Stephanie is on the right. Michael Woods is behind Stephanie, and I’m to Mike’s left dressed in all black playing with my cell phone. Well, in 6 hours we get started. I plan to post later tonight or tomorrow morning to report on Jerry Huffman’s keynote address.

Waiting for DELAYED flight at MKE airport

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Jim Raffel
on August 20, 2005
in uncategorized
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MKE = Milwaukee’s Mitchell International Airport for those who travel a bit less than I do. So, the Northwest mechanics did go on strike at 12:01am this morning. Even though our flight is delayed it looks like we will be leaving just a little less than an hour late. So, I am blogging for the first time over our new Verizon nationwide broadband service. Since our office is in the “country” it’s not very fast there, but here in the major metro are of Milwaukee I’m getting very close to cable modem speeds. Pretty cool technology for fellow road warriors, and I know there are some of you on my e-mail list.

We appear to be all set for User’s Group. The fun all starts with registration Sunday at noon. If you are joining us, I look forward to seeing you soon. If you are not able to join us, I will try to keep the blog updated each day with comments and pictures.

First 2005 ColorMetrix User’s Group Post

Published
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Jim Raffel
on August 18, 2005
in uncategorized
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For the next week, I will be utilizing the jimraffel.com blog as a way to keep anyone who cares up-to-date on the 2005 ColorMetrix User’s Group Conference. I decided to start today, because we just got done packing up all the boxes of materials for the meeting and shipping them off to the Mirage (see picture above).

As anyone who has ever done multiple presentations for a meeting knows, I am still working on all the content I will deliver at the meeting. I have done it enough times, however, that I no longer worry about not being done on time. Somehow or another the content always comes together. I also feel a bit of extemporaneousness in any presentation is a good thing.

The presentation I am most looking forward too is not until next Tuesday morning. I will be discussing the use of grey balance in the characterization of printing presses. I continue to be amazed how things which are old can become new again. As the previous post mentions we worked with people using grey balance as a characterization tool years ago, and all of a sudden it is back in vogue.

Well, I am looking forward to providing live reports from the conference. I may be the only one to read it, but it will still be fun. I will also try to post at least one picture a day, so those that did not come will wish they had!

Golden Nugget #9…Press Characterization and Grey Balance

Published
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Jim Raffel
on August 16, 2005
in gray balance
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*** Introduction ***

We will be in Las Vegas beginning Saturday for the 5th Annual ColorMetrix User’s Group Conference. The meeting runs through Tuesday, and we do not return until Wednesday, so there may not be a Golden Nugget next week. I am planning to try and use the www.JimRaffel.com site to post a daily update related to the User’s Group Conference, if you want to read about what we are up to. There is still time to register for our User’s Group Conference coming up August 21-23 at the Mirage Hotel in Las Vegas, NV. You will need to call us directly at 262-820-1131 to make all arrangements at this late date.

*** Jim Raffel’s Week 9 Golden Nugget…Press Characterization and Grey Balance ***

Back in my week 5 e-mail I mentioned how Eric Magnusson (www.leftdakota.com) mentioned that he is using a combination of L*a*b* values to arrive at tonal values (dot area) for ink jet proofs. This again, is because density which is used to calculate dot area is meant to be measured only on graphic arts ink sets. Well, as I began preparing my press fingerprinting piece for the User’s Group Conference, I decided to share some of my findings about improving press performance after a fingerprint (characterization) by utilizing grey balance techniques once included in our hexagon software product.

The techniques unfortunately depended upon density and thus only really work for tradition graphic arts CMYK ink sets. So I called the author of these formulas and found that he has also worked out a very reliable way to develop tone curves using L*a*b* like Eric’s method. While this is very promising, we need to test the math which will be happening in the coming months. Obviously we also need to test the outcome also. When all is said and done we should be able to offer a very easy and innovative way to create grey balanced curves for CTP devices.

Until then, however, I wanted to share the importance of adjusting grey balance as part of a press fingerprinting or characterization exercise. Here is the cheat sheet on how I go about it;

  1. Output a set of linear plates.
  2. Run the linear plates on press to standard densities.
  3. Ensure that all other press variables are as they would be during a production run.
  4. Double check the sheets for slurring doubling, etc.
  5. Measure the sheets to confirm correct density, TVI, Trap, Print Contract, etc…values.
  6. Use the “secret sauce” math in our hexagon program to create balanced grey cut back curves for your CTP device.
  7. Output a new set of plates with the cut back curves.
  8. At the same densities and TVI you should now have perfectly balanced color.

It sounds simple and while it is a bit more complicated than the above 8 steps make it sound, it is by no means rocket science. Want to know more? Join us a User’s Group (it’s not too late, really it’s not!).

Golden Nugget #8…Specification, Guideline, or Process Capabilities?

Published
by
Jim Raffel
on August 9, 2005
in GRACoL, guidelines, process capability and specification
. 0 Comments

*** Introduction ***

If you noticed there was not Golden Nugget last week, it is because I was on vacation. Please remember you can always visit www.JimRaffel.com to review an archive of previous Golden Nuggets. There is still time to register for our User’s Group Conference coming up August 21-23 at the Mirage Hotel in Las Vegas, NV. You will need to call us directly at 262-820-1131 to make all arrangements at this late date.

*** Jim Raffel’s Week 8 Golden Nugget…Is it a Specification, a Guideline or a Process Capability? ***

We are often asked how to set both reference values (sometimes called target values, or gold standards), and the tolerance window associated with the reference values that have been set. I will start by saying my choice with all other factors being equal is to set both the reference and tolerance based upon process capabilities. Process capabilities are the most difficult of the three to explain so I will begin with the other two.

We define a specification as a reference value and tolerance range provided by the print buyer. For example, consumer product company K writes into the print contract that all special colors must be maintained within 2.5 Delta E of the L*a*b* values they provide for the color. If you are thinking a specification is something like SNAP, GRACoL, or SWOP (not a breakfast cereal by the way), please read on to see the way we define them.

We consider SNAP (Specifications for Newsprint Advertising Production), GRACoL (General Requirements for Applications in Commercial Offset Lithography), and SWOP (Specifications for Web Offset Publications) to be industry guidelines. While I am POSITIVE I will get several e-mails letting me know how wrong I am on this, let me explain. I look at it this way. Unless one of the above guidelines has been written into a contract, it is just that a guideline. Once a print buyer adds a clause to the contract that says print will conform to SWOP, it becomes a specification. What’s the difference? Well, you loose money and customers if you do not achieve specifications written into contracts. Guidelines on the other hand are a great aim point for jobs and customers who do not provide written specifications.

Process capabilities are a whole different ball game. I will not be able to do the topic justice here, but we are devoting almost 1/2 day at the User’s Group Conference in less than 2 weeks to this topic. Basically process capabilities are determined by operating under normal conditions for an extend period of time. Over this period of time samples are collected and measured. For example, in an ink jet proofing environment you would run for an entire month to collect samples on different shifts and under different temperature and humidity conditions. The samples are then analyzed using statistical methods to determine mean (average) L*a*b* values, and the accompanying standard deviation of the aforementioned values. Your reference (or target) is then set to the mean L*a*b* values, and the tolerance is set to a factor of the standard deviation. In ink jet proofing we have found a plus tolerance of three standard deviations to be achievable 99% of the time. When speaking of Delta E, the minus tolerance is not a factor. If your mean is Delta E over time is say 1.5, and you then run proofs with a mean Delta E of .1, they will be visually acceptable.

So, for my week 8 Golden Nugget, I have once again chosen to enter controversial waters. I look forward to the e-mails questioning my statements above and offering alternative views. Also, remember you can simply add comments to each golden nugget at www.JimRaffel,com, and all readers will seem them even if they are not included in a later golden nugget.