Convert Pantone to CMYK

[ngs2600]

Hello All,

How do you determine the cmyk value for a Pantone.

I have a customer that wanted to make some last minute color changes to their files. They supply pantone numbers knowing we would have to convert them to CMYK values. We convert the Pantone values in Indesign CS5. When we got to press, the customer pulls out his pantone swatches and the printed piece is not close to the swathes. I know you will not get an exact match, but some of these were way off.

So, what has worked for you in the past?

Thanks!

 

[chevalier]

First the obvious - not all Pantone colors can be replicated using CMYK.

A good place to find out whether a color can be recreated using CMYK:
If a Pantone color is determined to be "Achievable in CMYK" the legacy Pantone books (prior to Pantone+) will have four dots :: below the Pantone name and number. If these dots are not present Pantone says you can't replicate it with CMYK. These colors are out of gamut and you will only be able to get within a certain range. There is also a venn-diagram type icon for colors determined to be "Achievable in RGB". I hold on to my legacy books for referencing this data only.

Example:
Pantone 205 C - NOT achievable in CMYK, achievable in RGB
Pantone 206 C - NOT achievable in CMYK, NOT achievable in RGB
Pantone 207 C - achievable in CMYK, achievable in RGB


The Pantone CMYK values built into InDesign, Photoshop, etc. are provided to Adobe by Pantone. Of course it doesn't tell you what substrate these values were determined upon so they are only "generally" useful.

The only way to realistically predict results is to have a calibrated proofer that most accurately matches your press sheet. Output a proof with your conversions and then compare to the swatchbook. Make sure you are matching to your customers swatch book or the one that will be used for press approval. If things don't match make adjustments in your files and reproof until you achieve a match.

 

[Greg_Firestone]

Hi ngs2600,

Just wondering if you are printing digital or offset/flexo. The reason I ask is that some RIPs have built in tables to better match Pantone colors to CMYK than their default values.

Otherwise, what chevalier said is correct - some Pantone colors don't have an close CMYK equivalent.

Regards,
Greg

 

[chevalier]

Just wondering if you are printing digital or offset/flexo. The reason I ask is that some RIPs have built in tables to better match Pantone colors to CMYK than their default values.

This is only relevant to whatever stock they built the conversions upon. If they are built off of LAB values as some of these prepress systems and RIPs are this can be further streamlined given that you have programmed your press stocks into the software.

 

[ngs2600]

Chevalier,

Thanks for the info. I did not know about the four dots in the Pantone legacy book. All I can find in the shop are swatch books supplied by ink manufacturers. Those books only list the build info, ex. 55.7 Process blue, 47.2 Rubine Red, 3 Process Black. Looks like a press trial will go along way to getting better results.

Greg,
This job was offset printing on a six color UV Komori. And we use RamPage for our Ripping solution. I was converting the color upstream though.

Thanks for the response.

 

[MacTwidget]

I would use the Pantone Color Bridge swatch book.
I trust the experts who created the PMS system to tell me what the closest CMYK equivalent is.

 

[Stephen Marsh]

I would use the Pantone Color Bridge swatch book.

Agreed.

I trust the experts who created the PMS system to tell me what the closest CMYK equivalent is.

If given a good L*a*b* value from Pantone and good proofing or press profiles from a print shop, I would trust a good print shops conversion over the "closest" CMYK value in the printed Bridge swatch book. I am not even sure if the CMYK swatch next to the spot is intended to represent the "best" or "closest" match, however it is good to visually explain the process of out of gamut simulations of spot colours to customers that demand a close match to a solid spot colour.


Stephen Marsh

 

[John Clifford]

Pantone colors (Pantone Solid that is) are formulated colors. If the color is "out of gamut" that means that it CANNOT be reproduced using CMYK. The most extreme examples are metallic and florescent colors. No matter what you do in converting them to CMYK, they will NEVER match a Pantone solid swatch.

If the client NEEDS that color, then they need to go to a fifth plate or accept the closest match and live with it. In printing there are a lot of things we can do, but this ain't one of them.

 

[Joe Duffy]

Pantone colors (Pantone Solid that is) are formulated colors. If the color is "out of gamut" that means that it CANNOT be reproduced using CMYK. The most extreme examples are metallic and florescent colors. No matter what you do in converting them to CMYK, they will NEVER match a Pantone solid swatch.

If the client NEEDS that color, then they need to go to a fifth plate or accept the closest match and live with it. In printing there are a lot of things we can do, but this ain't one of them.

Unless you have one of these...

 

[rich apollo]

How do you determine the cmyk value for a Pantone.

Either let me know what output profile you're using, or send it to me, and let me know what PANTONE library you want values for and I can send you a list of CMYK values specific to your output condition.

 

[ngs2600]

Thanks for all the responses.

I too would have suggested printing another spot color, but we have a six unit press. Job was four color process, one pantone and a strike through matte coating in the sixth unit.

Here is the list out Pantone colors the customer was looking for...
3015
2587
168
4625
201
130
153

I got the CMYK break down in Indesign CS5 using the pantone coated library and then converting to CMYK.

Balance of the job is still on press. I had to make an adjustment to about half of the colors once we got up to color. We got through it.
Again, I know a CMYK break down will never match a Pantone.

Thanks again for the feedback.

 

[Greg_Firestone]

Doesn't everyone print 7 color spot jobs????