Archive for the 'specification' Category

#52: GRACoL G7 Comments from the field

Published
by
Jim Raffel
on April 10, 2007
in GRACoL, blogging and specification
. 0 Comments

It has been an interesting couple weeks in the field for me. Color experts at four of the largest printing companies in the world have made almost exactly the same comments about the new GRACoL and SWOP data sets, and G7 methodology. I want to stress that the comments that follow are not mine, but are instead a summary of what I have heard from experts in the field who have to work with the data sets and methodology every day.

Data sets: The data sets are good and we will be using them. The data has clearly been massaged and is not wholly from press sheets, but good nonetheless.

G7 Methodology: The methodology is unnecessary for us. We have had our presses grey balanced for years.

It is good to have confirmation that the running to grey balance as many of us have been doing for years is validated. The G7 methodology is just one way of arriving at good grey balance with a specific set of inks. While it would be wonderful if everyone ran perfect G7 or SWOP ink sets those of us who are honest know this is not the case.

This explains why these very large and successful printers have chosen to achieve pressroom grey balance in their own way, and then run to match the proof created with the data sets mentioned above.

The experts mentioned above also validate that having quality “standard” data sets is critical to being able to print the same job in multiple plants control by multiple owners all over the world. It does not appear, however, to be critical that each vendor use exactly the same process to achieve grey balance on press as long as grey balance has been achieved. (More than one kind of mouse trap can be used, and G7 may or may not be a better mouse trap.)

#33: Thoughts on GRACoL 7 and Standards in General

Published
by
Jim Raffel
on May 4, 2006
in CGATS, GRACoL, blogging, conferences, flexography, guidelines and specification
. 1 Comment

Sunday, Monday, and Tuesday of this week I was in Louisville at the FFTA Annual Forum & INFO*FLEX exhibition.  It was my first time attending this event and I was impressed.  We even got to spend Tuesday evening at the Six Flags Kentucky Kingdom theme park in Louisville.  I must say it was fun not having to wait in line for any of the rides (the park was closed to the public).

I was busy assisting one of our distributors (ColorManagement.com) with booth duty Sunday and Monday, but I did manage to attend several technical sessions focused on Color Management Tuesday.  One of these sessions was about the still fairly new Printing Across Boarders (PAB) initiative.  At the urging of Adam Dewitz over at Printmode.net I resumed receiving e-mail from the [pab] forum several weeks ago, so was interested to hear what was happening.

The primary focus of the presentation by Gerald Gerlach of Integrity Graphics was the GRACoL 7 (G7) methodology.  It was during this presentation, and over the subsequent 24 hours that I began to solidify my current overall feelings about G7 and more importantly about graphic arts standards in general.

For my entire career in the graphic arts (more than 20 years now) I have nibbled at the edges of the standards community.  I have always found it fascinating and have felt I had something to contribute.  While my main role in life is now selling, I am still a pretty fair graphic arts technician when I need to be.  I have not been more involved in the standards community for one reason; time.  Those who carry the vast majority of the standards load in this industry do so as volunteers.  While they may be on a company payroll somewhere I assure that only a very small percentage are paid to do only standards work.

These people give up evenings, weekends, and other valuable personal time so we can have graphic arts standards.  I wish to say to all of you (and you know who you are) THANK YOU!  So, perhaps instead of standing on the sidelines and criticizing (constructive or otherwise) all of us should be saying “how can we help you.”

While I do not completely agree with the G7 methodology, I do agree it is a step forward.  I believe this because our competition in the Graphic Arts industry is not other printers.  It is other communication mediums.   Can you imagine television succeeding without any standards?  Can you imagine the internet succeeding without any standards?

We as an industry need the ability to print an image consistently anywhere in the world.  This is the true goal of G7 as far as I can tell.  While I feel in the case of many printers this means you must “dumb down “ your press, the trade off for regional, national, or international print buyer makes this consequence of the methodology worth while.  Any printer can still apply their “secret sauce” technology to specialty jobs.  Just because you can print to G7 does not mean you must print to G7.

In conclusion, I want to ask the working members of BRIDGS, CGATS, FIRST, GRACoL, SNAP, & SWOP….How can I help?

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.