CMYK to Pantone converter

Re: CMYK to Pantone Converter

Re: CMYK to Pantone Converter

I have attached a PDF that has 4 steps to do this inside Illustrator. Another way in addition to the one shown in the video link that was submitted by planet_that_spins.
 

Attachments

  • StepsToConvertCMYKtoPMS.pdf
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The Pantone library contains colors you cannot make using CMYK colorants. For example, what might be called fire-engine red -- Pantone 185 -- cannot be duplicated in the CMYK world. The closest you can come is 100% magenta plus 100% yellow (which, by the way, is Pantone 485).
Converting CMYK to PMS185 is EXACTLY what I am trying to achieve-- lol
 
hi xMattx, YES there is a lot of difference in creating designs for web and print. Also it is depending on designs you are creating, generally all presses prints with CMYK. In special cases it is required Pantone colors, i.e. normally called as SPOT COLORS. Pantone colors are mixture of CMYK color and printing required color directly. Pantone colors are identifying with Pantone #. Based on your requirement use Pantone colors which are already available in all designing apps. Trapping knowledge is essential if you are using pantone colors.
 
Pantone to cmyk or cmyk to Pantone

Pantone to cmyk or cmyk to Pantone

The new specidication from Pantone lists LAB as the conversion color spcae, Adobe products (CS5) stil use RGB so I'll ask this how serious are you?
 
Hi David. Not sure what you mean here...Adobe still using RGB?

I haven't checked the the CS 5.5 suite but the Pantone conversion to CMYK tables specs are now based on LAB specs, Corel moved there with X5 and my CS 5 uses RGB values for Pantone to CMYK conversions.
 
I haven't checked the the CS 5.5 suite but the Pantone conversion to CMYK tables specs are now based on LAB specs, Corel moved there with X5 and my CS 5 uses RGB values for Pantone to CMYK conversions.

Well, the RGB values might be displayed (depending on preferences of the user), but any underlying conversion in Adobe CS from Pantone to CMYK would be through either an ICC connection space (LAB)...or a reference to a process library, not an actual RGB->CMYK conversion. Even then it would be RGB->LAB->CMYK, right?
 
I don't know about CS5 but Pantone has for decades provided RIP vendors with the Lab values of their spot color libraries. That allowed the RIP vendors to create their own simulations in CMYK according the the capabilities of an output device (if known) e.g. an inkjet plotter.
I just don't think the Pantone Lab values were available to the general public.
The Lab values in PShop were similar (i.e. the ones you see in the color picker menu) but not always the same as the values that Pantone provided RIP vendors.
Has that changed? And are they now the same?

best gordo
 
Has that changed? And are they now the same?

I'm not sure they're even the same within the differing applications within CS, Gordo. ;)
My Rip values did indeed differ from Adobe Colorpicker (Pshop), though were close. And yes, the general public hasn't had access to the Lab values except through third party apps, to my knowledge. I had it explained to me from Pantone a few years ago that the Lab values are not "official", but offered primarily as a convenience for the purposes you described. The only thing truly "official" and apparently unchanging through the years have been the ink formulas.
 
Well, the RGB values might be displayed (depending on preferences of the user), but any underlying conversion in Adobe CS from Pantone to CMYK would be through either an ICC connection space (LAB)...or a reference to a process library, not an actual RGB->CMYK conversion. Even then it would be RGB->LAB->CMYK, right?

Well the connection space is corect however the CMYK values used in the application as specified by Pantone specifications are different then Adobe as Adobe uses the old Pantone specifications which are based on RGB values.

Pantone created the new LAB spot color specification during the Alpha cycle of CorelDRAW X5 so Corel incorporated them in to X5. Adobe didn't bother updating CS4 at the time and has ignored them as far as I can see for CS5. As far as CS5.5 I do not know.

Spot colors are a mess, Pantone creates the specifications Adobe ignores it, some RIPS adopt the new LAB based conversion tables some do not.

Best keep your act together when it comes to spot color conversion, I use the LAB values as they are MUCH better.
 
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I'm not sure they're even the same within the differing applications within CS, Gordo. ;)
My Rip values did indeed differ from Adobe Colorpicker (Pshop), though were close. And yes, the general public hasn't had access to the Lab values except through third party apps, to my knowledge. I had it explained to me from Pantone a few years ago that the Lab values are not "official", but offered primarily as a convenience for the purposes you described. The only thing truly "official" and apparently unchanging through the years have been the ink formulas.

They will be the same for identical CM settings and I mean every setting.
 
They will be the same for identical CM settings and I mean every setting.

I don't understand what you mean.
The Pantone table of Lab values that they supply to RIP vendors is basically a text file - a look up table. Therefore there are no CM settings that will change the values.
For example, for PANTONE 338 C the official values are: 77.68, -31.96, 1.37
In PShop the values for that color are: 78, -34, 4
Similar - but not the same.
And, if I change my CM settings in PShop the color picker Lab values do not change - which suggests that Adobe is using Pantone's look up table.

thx, gordo
 
I don't understand what you mean.
The Pantone table of Lab values that they supply to RIP vendors is basically a text file - a look up table. Therefore there are no CM settings that will change the values.
For example, for PANTONE 338 C the official values are: 77.68, -31.96, 1.37
In PShop the values for that color are: 78, -34, 4
Similar - but not the same.
And, if I change my CM settings in PShop the color picker Lab values do not change - which suggests that Adobe is using Pantone's look up table.

thx, gordo
>For example, for PANTONE 338 C the official values are: 77.68, -31.96, 1.37
The official CMYK values move in a properly colormanaged environment.

PS will properly color manage the conversion. For example Pantone 338C on my system using Adobe CMM, in an RGB document, relative colorimetric and 3 different CMYK profiles develops 3 different CMYK values with the picker, 36 1 29 0 - 48 0 34 0- 49 0 35 0. Prophoto RGB document, from a Kodak TIC 360 CMYK document, that matches my first CMYK attempt the 338C converts to 36 1 29 0 so the CMYK profile is controling the conversion from spot color to CMYK.

AI it seems uses a CMYK table to convert from spot color to CMYK, it converts totally different from PS. I've confirmed this using CorelDRAW as it has the ability to switch between CMYK, RGB and LAB. The CMYK tables match AI.

PS and CorelDRAW X5 and Corel Photo-PAINT X5 using LAB conversions are extremly close + or - 1 point so it appears that PS CS5 as well CDGS X5 are using LAB however AI does not. A test confirms that InDesign does not either, it uses the same process as AI.

The Pantone Specification for converting Spot Color to CMYK is to consult a LAB table, it appears that PS CS5 and CorelDRAW Graphics Suits X5 are doing it correctly.
 
@ David Milisock. Ok, I see where I misunderstood you.
It's fine that the CMYK values change based on the destination profile.
The problem is that Pantone has different Lab values for the individual colors. So, depending on which LUT is being used the target Lab value for a specific color can be different and hence the resulting CMYK screen tint values. So you're dealing with two variables (the Lab and CM settings) instead of one (the CM settings).

best, gordo
 
@ David Milisock. Ok, I see where I misunderstood you.
It's fine that the CMYK values change based on the destination profile.
The problem is that Pantone has different Lab values for the individual colors. So, depending on which LUT is being used the target Lab value for a specific color can be different and hence the resulting CMYK screen tint values. So you're dealing with two variables (the Lab and CM settings) instead of one (the CM settings).

best, gordo

Yep, the problem arises with repeat work handeld via older processses and if you have the print device handle the conversion. This can be a mess different tables all over the place, I just convert in the application and send a tagged PDF to the destination device. Spot color is already converted to the best CMYK possible based on LAN specifications and then as CMYK to the media profile.

Press work just flies out as spot and digital goes through the application based conversion process.
 
Ok this is throwing in a problem at a late stage…*but it is possible to use Lab values in InDesign and then convert to the output intent using PDFx1a…which would theoretically give closest match. I used to do this even to export to PDFx4 until I found I had problems with this on gradients fading to paper, because the paper (0% colour) also got defined as Lab, which in the RIP would try to match resulting in full Spot colours benefiting but gradients fading to paper messing the whole thing up.
Today I use the Pantone bridge (coated and uncoated) look at the application values, some times also use colourshopX (on G5 and older computer) and often a little common sense (aka experienced intelligent guess) to, if possible keep the number of primary colours down to a minimum. (If time permits and the intention is to determine, company brand colours I'll try sneak some swatches in a gutter of some job on a similar stock)
 

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