A Pantone colour is a specific ink, mixed before it goes on the press. CMYK builds every colour from dots of four inks. So a Pantone colour in a CMYK job is always a simulation, some simulate well, and some can't be simulated at all. That leaves two decisions: keep the colour as its own ink (a spot colour) or print it from CMYK (process), and if process, which four numbers.
Spot or process
Keep it as a spot ink when:
- It is metallic or fluorescent. No CMYK value looks like either.
- It falls outside CMYK and has to be right. Bright oranges, greens and blues are the usual casualties. The check is below.
- The exact brand colour has to match on every job, such as packaging or a long run where a logo sits on a large flat area.
- The job is one or two colours anyway. A letterhead in black and one brand colour can print from two spot inks instead of four process inks.
- It is a technical plate: white ink, varnish, spot UV, foil or a die line. None of those are colours, but they travel in the file the same way, as a named spot.
Print it in CMYK when the job is full colour already (photos), when it is printed digitally, and when the colour fits. On a press, every spot ink on top of CMYK is one more plate and one more ink unit. Many digital presses print CMYK only. Ask the printer what a spot costs and whether they can run one.
Where the CMYK numbers come from
Pantone's colour data is licensed, and the authoritative CMYK value for a Pantone colour is Pantone's own. In this order:
- The brand guide. If it lists a CMYK value next to the Pantone number, use it. Someone already chose that conversion and approved it.
- A Pantone Color Bridge guide. The printed fan guide shows each solid ink next to its CMYK simulation, with the CMYK values under it, so you see on paper how close the simulation gets before you choose it.
- Pantone Connect, Pantone's web app and design-app plugin. The free tier is limited, and CMYK and Lab values have been in the paid tier; check Pantone's current plans before you count on them.
In the design apps:
- Adobe Illustrator, InDesign and Photoshop stopped including most Pantone libraries in 2022. Pantone colours now come through the Pantone Connect plugin, which needs a paid licence.
- Affinity Designer and Publisher have included Pantone palettes in the Swatches panel, Color Bridge among them, under Serif's licence from Pantone. Check that your version still has them.
- In any app, including the free Scribus, you can type the CMYK values from the brand guide or the Bridge guide into a swatch of your own.
Pantone solid swatches in design apps are generally defined in Lab. Switch one to CMYK and the app converts it through the document's CMYK profile, which is not the conversion behind the printed Bridge guide, so the numbers can differ. When you have a CMYK value from the brand guide or the Bridge guide, type it in rather than letting the app convert.
Check the letter after the number: C is for coated paper and U for uncoated. It is the same ink, but it looks different on each, so the simulations differ too. Use the one that matches the paper.
Check whether it fits in CMYK
Lab is the neutral way to describe a colour: L is lightness, a runs from green to red and b from blue to yellow. It doesn't depend on any ink, screen or paper, and print measures it under D50 light. Pantone publishes a Lab value for each colour (in Pantone Connect's paid tier, or in your design app when you set the swatch's colour mode to Lab).
To see what CMYK does to a colour, convert its Lab value to CMYK through your printer's ICC profile, then convert that CMYK back to Lab. If the colour fits, it comes back the same. If it doesn't, the difference is what the press will lose.
On Debian and Ubuntu, apt install liblcms2-utils installs transicc, and
colord-data has the FOGRA39 profile used here (in
/usr/share/color/icc/colord/). Use the profile your printer names if they
give you one.
We can't print Pantone's Lab values here, because they are licensed. The
example is the screen orange #FF6600 instead, whose Lab value comes straight
from the sRGB standard:
echo "255 102 0" | transicc -n -t1 -i "*sRGB" -o "*Lab"
63.1555 57.0600 72.6436
Put in your own Lab value and convert it to CMYK:
echo "63.16 57.06 72.64" | transicc -n -t1 -i "*Lab" -o FOGRA39L_coated.icc
0.0000 69.9016 99.3683 0.0000
That is C 0, M 70, Y 99, K 0. Yellow is at its maximum with no cyan or black, which is a colour pushed against the edge of what the inks can do. Convert the CMYK back to see what it prints as:
echo "63.16 57.06 72.64" | transicc -n -t1 -i "*Lab" -o FOGRA39L_coated.icc | transicc -n -t1 -i FOGRA39L_coated.icc -o "*Lab"
60.9666 49.2227 61.7813
transicc also prints a two-line LittleCMS banner for each run; it goes to
stderr, not into the pipe. -t1 is relative colorimetric: colours that fit
come through exactly, and colours that don't are moved to the nearest
printable one.
The same round trip for three colours, through FOGRA39 (LittleCMS 2.16):
| Colour | Lab asked for | CMYK | Lab it prints as | ΔE 2000 |
|---|---|---|---|---|
Orange #FF6600 |
63.2 57.1 72.6 | 0 70 99 0 | 61.0 49.2 61.8 | 3.3 |
Green #00C060 |
68.4 −58.3 36.2 | 74 0 81 0 | 63.5 −45.2 30.6 | 5.5 |
Navy #2B4C7E |
31.8 0.9 −32.5 | 88 59 0 38 | 31.8 0.7 −32.5 | 0.2 |
The navy fits: 0.2 is rounding. The orange loses saturation (chroma, the distance from grey, drops from 92 to 79), so it prints as a duller orange. The green loses more. These are colours a screen can show; a bright Pantone orange or green is made to go further than a screen or CMYK can, and will lose more.
ΔE is how different two colours are. We worked it out from the two Lab values with the CIEDE2000 formula, which weighs the difference the way eyes see it. The older 1976 formula is a plain distance and reads much higher for saturated colours: 13.6 for the orange. When a printer quotes a tolerance, ask which formula they mean.
A formula with no profile doesn't know the inks or the paper. Our
HEX to CMYK converter uses one, and says so on the
page: it turns #00C060 into 100 0 50 25, where the FOGRA39 profile gives 74 0
81 0. That is fine for a rough idea and wrong for a press. Its Lab is also
measured against screen white (D65) rather than print's D50, so a Lab value from
a swatch book lands slightly off in it. Converting whole images and documents
properly is in
how to convert RGB to CMYK for print.
When it doesn't fit
You have three honest choices:
- Accept the simulation. Pick the CMYK value from the Bridge guide or the brand guide, and approve it on a printed proof, not on screen.
- Keep the spot ink. The only way to get the real colour.
- Ask about expanded gamut. Some printers add orange, green and violet inks to CMYK, which reaches further into exactly the colours CMYK misses. Pantone sells an Extended Gamut guide for it.
Keeping it as a spot ink
In the design app, set the swatch's type to Spot (in InDesign and Illustrator, Color Type in Swatch Options; in Scribus, Is Spot Color in the colour's editor). Name it exactly as the brand guide and the printer do. The name is what the printer's RIP sees: two spellings of the same colour are two plates.
Then check the plates before you send the file. InDesign has Window › Output › Separations Preview, Illustrator Window › Separations Preview, and Acrobat Pro Output Preview among its print production tools. From the command line, Ghostscript writes one image per plate and names each file after its ink:
gs -q -sDEVICE=tiffsep -r72 -o plates.tif logo.pdf
ls plates*
plates(Black).tif
plates(Brand Orange).tif
plates(Cyan).tif
plates(Magenta).tif
plates(Yellow).tif
plates.tif
A spot ink called Brand Orange gets its own plate. A CMYK-only job should
give you exactly four, plus the composite plates.tif. Don't use
-sDEVICE=inkcov for this: it reports coverage in CMYK only and folds the spot
into the four process inks.
The opposite problem is common too: a CMYK job with a logo that still carries a
Pantone spot, which shows up as a fifth plate. Fix it where the logo was made,
or in InDesign's Ink Manager (in the Swatches panel menu) with All Spots
to Process. Don't count on a generic colour conversion to do it: Ghostscript
10.05.1 with -sColorConversionStrategy=CMYK left the Brand Orange plate in
place in our test.
Without a design app
If you have no design software (a Chromebook, a phone, a locked-down laptop) and the printer wants a PDF with a named spot ink, Popcorn can define one: a spot swatch with tints and overprint, finishing presets for white ink, varnish, foil, spot UV and die lines, and a Proof panel that shows each plate on its own. It exports the spot as a real separation in a PDF/X file.
It ships no Pantone library. Import a swatch book you are licensed to use (ASE, CSV, GPL, SOC or CxF; Adobe's .acb isn't supported) with Import color book in the Swatches panel, or write your own CSV with the name and Lab value:
name,L,a,b
Brand Orange,63.16,57.06,72.64
A Lab row comes in as a spot ink. In a PDF/X-4 export it keeps that Lab value as the ink's appearance; PDF/X-1a allows no Lab, so there it falls back to the swatch's CMYK values. Designing is free without an account; exporting needs one, and the print PDF needs a paid plan. Popcorn's own click-path for finishes is in Spot colors, foil, white ink & spot UV.
Our browser tools, honestly
None of our tools knows a Pantone colour, and none converts through an ICC profile.
A generic name and a distance on screen, not a Pantone number or a CMYK recipe.
What goes to the printer
- Process: the swatch holds the CMYK value from the brand guide or the Bridge guide, its type is Process, and the plate check shows four plates.
- Spot: the swatch is named exactly as the printer expects, its type is Spot, and the plate check shows that plate with that name.
- In the order, say which it is ("PANTONE … C as a spot", or "simulated in CMYK"), and ask for a printed proof when the colour matters.
The rest of the file (bleed, image resolution, PDF/X) is in how to make a print-ready PDF.
