Hi Ray,
I agree with you about the lack of information from those CMYK values from the Pantone Solid to Process guide.
have you ever notice that those CMYK values from the Pantone Solid to Process guide, were allways made with 3 colors? Never 4!
The new Pantone Bridge, now uses 4 colors when needed. This make better CMYK simulations than previously. But this brings a new communication problem when graphic designer specify Pantone reference for CMYK conversion.
ALSO, yes, the new CS 2 Suite let you use Lab values for Pantone match in CMYK, BUT, be aware the default rendering intent used in the Color Settings AND the Black Point Compensation option will change the way all CS 2 app (Photoshop, Illustrator, INDesign, etc.) will calculate the CMYK simulation values. Specially for the dark colors.
Make a test using Black Point Compensation, On and OFF in Relative Colorimetric, with Pantone 669 for an example. Then, change your default rendering intent to Absolute Colorimetric in your Color Settings.... You will see that the simulation is better!
Here are the numbers for Pantone 669 (Lab: L23 a20 b-27) to US Web Coated SWOP v2:
Relative Colorimetric WITH BPC: CMYK values: C84 M93 Y33 K24 Lab values (AbsC): L25 a14 b-18
Absolute Colorimetric (BPC changes nothing) CMYK values: C90 M100 Y28 K34 Lab values (AbsC): L24 a17 b-25
DeltaE94 match: RC with BPC: 8.84 AbsC: 2.99
DeltaE Lab match: RC with BPC: 11.0 AbsC: 3.74
Make your own conclusions.
Hope this will help!
Louis Dery v.p. Nouvelles Technologies / New Technologies TGLC inc. www.tglc.com 418-877-9114 Color management for the Pros, with PerfX Color Management™ ICC profilers and NO tweak! |