Colour Tolerance

[Cornishpastythighs]

I was hoping some of you could help me with a recent customer demand. A new customer has requested we send them Spectro data of the press colour match and run using CIE94. We have always used DeltaE CMC for our other customers without issues. We verify colour using a software product from XRite called IQC along with a 939 Spectro. Trouble is IQC does not have CIE94 as an option.
It has CMC, DE* and CIE2000.My question is would CIE2000 be close to CIE94? The customer is also using a 528 Spectro to compare our samples.
Thanks

 

[gordo]

They should be close (94 and 2000). You should be able to convert between the different deltas using the calculator here: Welcome to Bruce Lindbloom's Web Site

 

[michaelejahn]

They should be close (94 and 2000). [/url]

Close as in *works with hand grenades*

Cornishpastythighs - can you to tell us what sort of printing we are measuring (graphic arts - vs - textiles? )
-- and if you have basic of professional version IQC ?

( if you scroll down, you can see the *difference* in the math between CIE Delta E 94 and CIE Delta E 2000 )

http://docs.google.com/Doc?id=dfwf37zj_1077dfc3qxhq

CIE Delta E 94
For graphic arts applications, K1 = 0.045 and K2 = 0.015.
For textile applications, K1 = 0.048 and K2 = 0.014.
The color difference, or ΔE, between a sample color L2a2b2 and a reference color L1a1b1

CIE Delta E 2000
In this implementation KL = KC = KH = 1.0.
The color difference, or ΔE, between a sample color L2a2b2 and a reference color L1a1b

 

[Cornishpastythighs]

- can you to tell us what sort of printing we are measuring (graphic arts - vs - textiles? )
-- and if you have basic of professional version IQC ?

We are a Package printer with around 2000 special colours. I believe we have IQC Professional and have been working with it for around a year or so. I contacted xrite directly and they confirm that CIE94 was never put into IQC when the software was developed.
Thanks

 

[michaelejahn]

- I contacted xrite directly and they confirm that CIE94 was never put into IQC when the software was developed.

Yes, nor would I imagine that would have any reason to add something developed in 1976 to your software.

So, If i were in your shoes, I would ask just why they insist on using old and stinky math ( of course, much more diplomatically ) and share that historically, CIE Delta E 94 is old and found to have errors that were corrected with CIE Delta E 2000 and they should be *close* enough.

 

[Cornishpastythighs]

Michael Jahn
Good advice and thank you sir.

 

[Stephen Marsh]

Even if both instruments are measuring with the same dE system, what would the inter-instrument deviation be?

http://www.cyberchromeusa.com/Color-QC-and-Matching-Blog/bid/76644/Tip-4-Inter-Instrument-Agreement


Stephen Marsh