Question about solid to process conversion...

[Skittizay]

so, being that i'm in prepress, i have quite a few swatch conversion booklets...my quesiton is this...

why do different books have different CMYK conversion values...

for example, i have 2 pantone solid to process coated guides. 314C converts to C100 M0
Y9 K30 on one book and C100 M4 Y14 K18 on the other...what logical explanation is there for this??? i've been trying to figure this out for the longest time...any help would be appreciated.

thanks!

 

[gordo]

so, being that i'm in prepress, i have quite a few swatch conversion booklets...my quesiton is this...
why do different books have different CMYK conversion values...
for example, i have 2 pantone solid to process coated guides. 314C converts to C100 M0
Y9 K30 on one book and C100 M4 Y14 K18 on the other...what logical explanation is there for this??? i've been trying to figure this out for the longest time...any help would be appreciated.
thanks!

Because Pantone updates and "refines" their recipes - in your example going from a 4/C recipe to a 3/C recipe makes for a more reliable on press and in prepress screen tint build while delivering, hopefully, the same color appearance (in the swatch books anyway).

gordon p

 

[Skittizay]

hmm, i don't quite understand what your saying...is there another way to explain it???

thanks again!

 

[gordo]

hmm, i don't quite understand what your saying...is there another way to explain it???
thanks again!

Sure. In your example one recipe for the PMS simulation was: C100 M4 Y14 K18. Because there are 4 colors to make the simulation there are 4 things that could vary in either plate imaging or on press.

The other (and likely more recent) recipe for the same PMS simulation was: C100 M0 Y9 K30. Since M is now zero, Pantone has eliminated one of the variables. The eliminated the M by upping the black component as well as reducing the Y component. Since black is not a chromatic color (it darkens but does not effect color) by increasing it and reducing the chromatic color (M & Y) they have made the color more stable on press as solid ink densities naturally vary through the press run. Also, With Y now at 9% rather than 14% the impact of dot gain variation is also lessened - again, leading to more color stability on press.

hope that's clearer. gordon p

 

[Skittizay]

great thanks!

 

[TerryWyse]

hmm, i don't quite understand what your saying...is there another way to explain it??

DIFFERENT process builds can actually produce the SAME color, at least from a colorimetry standpoint.

Since the color you described is basically a "dirty" cyan, the unwanted color could be either magenta+yellow or these could be removed and replaced with black....thus producing the same color on press but with a different build. Naturally, the build with black as the unwanted color would be generally more stable than if magenta+yellow was used as the unwanted color/gray component.

Regards,
Terry

 

[ColorGeek]

Good points by Gordo and Terry. I would also elaborate on Gordo's original point that Pantone, over the last 10 -15 years, has revised their recipes several times. You may have two Pantone guides that differ in age. The best thing to do is to make sure you (and your customer) have new and current guides to refer to. You can double check this on Pantone's website. Click here: Graphics - PANTONE FORMULA GUIDE coated, uncoated, matte then click the "check if your guide EXPIRED" link on the right. Throw away any old guides - they are confusing things.

Dan Gillespie
---------------
Director of Technical Services
The Color Management Group

 

[jstanzione]

Clarification to Dan Gillespie's post on 11/24/09

Clarification to Dan Gillespie's post on 11/24/09

To all:

I just wanted to clarify one point in Dan's post from 11/24/09.

The 'check if you guide expired' link refers to the PANTONE FORMULA GUIDE, which displays only the solid PANTONE colors with the ink mixing formulations - it does NOT have CMYK simulation data.

The latest edition of the guide which compares PANTONE solid colors with CMYK simulations, is known as PANTONE COLOR BRIDGE. You will also find this product availabe on the Pantone Web site.

Best regards,

John Stanzione
Manager - Technical Support
Pantone LLC
Wholly-owned subsidiary of X-Rite, Inc.
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