What to expect from G7 expert/consultant?

[J]

Hi,

If a G7 expert comes to our shop to set us up so that we can apply for master printer certification, what is the basic process or steps that they would follow and about how long does it take?

John

 

[rich apollo]

Re: What to expect from G7 expert/consultant?

Check it out here http://www.gracol.org/experts/G7 MastersProgramProcedures.pdf

You can do a few things before the consultant gets there:

• read the G7 How-To guide
• ensure the proper operation of your equipment (press, platesetter, processor, proofer)
• if you have a spectrophotometer or a spectrodensitometer you could perform an early run to see where/if you can hit the colorimetric aims for primary and overprint colors

Contact me off-list and I'll send you a nice pre-calibration run document a friend of mine built.

rich

 

[ColorGeek]

Re: What to expect from G7 expert/consultant?

First of all, IDEAlliance would be quick to correct that, it is officially a Master Printer "Qualification" not "Certification". Consultants get certified as experts and master printers get qualified. It's confusing, I know, but I thought I would mention it.

Rich gives you good advice, I'm just adding to it. An expert should start by linearizing the plates. In the beginning, IDEAlliance did not specify/suggest this but now they do. Linear plates go on press and the first make ready is very important in hitting those colorimetric aims for primary and overprint colors, that Rich mentioned.

The press form most experts use would have some sort of P2P chart on it. These charts would get measured in ColorPort and the measurement data exported. Import data into IDEAlink Curve to generate curves. Enter curve info to affect plates somewhere. Image new plates, put them on press, and make ready again. Hit those aim points again and you're done.

Now keep in mind that each press and paper would have this done separately. If you did the leg-work Rich suggested and everything went perfectly you could do 1-2 setups per day. If there is any bumblin-and-stumblin, things not working right, learning as you go. You'll be lucky to get one setup per day.

Also, some experts might take the sheets from the second run and measure them to create a custom profile for your proofing. I recommend otherwise. I would use the supplied GRACOL profile or measurement data and roll-my-own. I think that if you get everything right the pressman should be able to match the proofs that use the supplied standard measurement data as reference.

Dan Gillespie
ColorGeek, Inc.

 

[MackyMoto]

Re: What to expect from G7 expert/consultant?

Could someone give me the Cliff Notes explanation of what G7 is. All I could derive from the IdeaAlliance web site is that G stands for gray and 7 represents the number of inks used. One of my vendors keeps touting that they are a G7 shop, but he couldn't explain what that meant, and honestly I'm skeptical. I think they're confusing G7 with Gracol 7.

 

[gordo]

Re: What to expect from G7 expert/consultant?

GRACoL is the IDEAlliance Committee formed in 1996 to develop a document with general guidelines and recommendations for use as a reference source across the industry for quality color printing.

GRACoL 7 is the current version of the GRACoL publication - includes a definition for gray balance and recommends characterization data for commercial offset printing on a #1 coated sheet

G7 refers to specific methods to calibrate proofing systems and presses based on principles of digital imaging, spectrophotometry, and computer-to-plate (CtP) technologies.


best, gordo

 

[MackyMoto]

Re: What to expect from G7 expert/consultant?

Thanks Gordo. So does the G7 process require 7 colors?

 

[gordo]

Re: What to expect from G7 expert/consultant?

Nope. G7 is for four color process printing. The 7 colors are CMYK and RGB - the RGB result from the overprints of the 3 process colors C,M, and Y (Y+M = R, Y+C = G, M+C=B). "G" is for Gray balance which takes on a new importance with these guidelines.

best, gordo