Printing to International Standards with G7: Mythbuster?

What is G7 and what does it mean to you?

IIDEAlliance's G7 is a revolutionary new methodology for calibrating proof-to-press and press-to-press across any printing method.

Developed by our industry's leading color experts, the G7 methodology includes revolutionary techniques for dramatically improving print quality and consistency.

As G7 'Experts', we can provide step-by-step training within your company to calibrate proofing and printing systems using the latest G7 methodology.

G7 methods have been adopted worldwide: files and proofs created anywhere in the world using the G7 methods, can be matched in any pressroom.

For your business, this means improved color fidelity, press sheets that match the proof resulting in quicker make-readies, faster time-to-market, and lower manufacturing costs.

Take the first simple steps toward better printing: contact us at Cathay America: jpasky@gmail.com

G7 on a Post-it Note

A guide to getting repeatable color matches on press, everyday

The G7 methodology has been critisized as being 'too complicated'.

It is not.

Here is a very nice summary of the process that was orignially published by Glenn Andrews of Schawk in Los Angeles. (with a couple of small changes of mine).

1. Use good paper and good ink.

2. Have the press in good running condition.
3. Include color bars with solids, overprints, a 50%C 40%M 40%Y neutral and a 50% or 53% midtone K patch.
4. Run to industry-standard solid ink densities.
5. Mid-tone density must be 0.54 plus the density of the paper.
6. 50%C 40%M 40%Y neutral must be exactly the same color and value as the mid-tone K.

A press sheet run to these specifications will match a good proof.

Monday, November 17, 2008

Mythbuster?

In a continuing to think about how ink-sets around the world seem to be more similar that different, I tripped across another interesting set of numbers while cleaning out some old files. I fed these into my color comparison software to see what the differences would read.

Following is a comparison of Japan Color Standard vs. the recommended ISO L*a*b* values:

ISO

c 55 -37 -50

m 48 74 -3

y 89 -5 93

Japan Color

c 52 -36 -49

m 47 75 -3

y 87 -5 88

ISO

R 47 68 48

G 50 -68 25

B 24 27 -46

Japan Color

R 47 69 46

G 47 -68 23

B 21 22 -47

Comparing the two standards, here are the delta E values I got:

c 1.62

m 1.01

y 1.62

R 1.14

G 3.09

B 3.58
(btw...Japan Color Standard for black is 16.5 vs. ISO of 16.0)

All these readings are well within the published tolerances: ISO <5.0 and Japan Color <6.0

I've always been told that inks from Japan are 'different' from the inks we use in the States.

Is this comparison of the published standards a 'mythbuster' ?

I'd be interested in your comments.

6 comments:

laura said...: printing four color poster is a great artifact to create a long impression with your customers, this is an excellent choice. Thanks!; October 8, 2009 at 6:27 PM
Cherry Red said...: Hi, I think your color difference calculator used DeltaE2000 formula to calculat the color difference. ISO 12647-2 tolerances are based on DeltaE1976 formula. If you use 1976 formula to calculate the Delta E between ISO and Japan color, based on the values you have given in your post, the Delta E of yellow crosses 5; December 8, 2009 at 4:15 AM
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I m From Online printing company; March 11, 2010 at 3:48 AM
Anonymous said...: Thanks for sharing about japan color std vs iso label !!
Very good calculation!!
I agreed,inks from Japan are different!! Printing Company Australia; February 25, 2011 at 2:56 AM
Excell Print said...: Hi I am visit your blogs and see its. It is nice blogs. I am impressed from your blogs. Some Printing companies are printed quality products.; July 15, 2011 at 4:36 AM
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