Article · Brandon Warrell

Rich black vs 100K black: which black should you use in print?

By Brandon Warrell ·October 31, 2026

Use 100K black (0/0/0/100, black ink only) for body text, small type and fine lines. Use a rich black, which is 100K plus some cyan, magenta and yellow, for large solid black areas, and build it to the numbers your printer gives you. Keep registration black, which is 100% of every ink, for crop and registration marks only.

Which black should you use in a CMYK print file?

Here are the common blacks side by side. Total ink is the four percentages added together.

The rich black rows are examples, not a standard. Printers publish different builds for their own presses and paper, so ask yours before you set one.

What is 100K black, and why can it print as dark gray?

100K is black ink on its own, with no cyan, magenta or yellow under it.

Over a big area it can look weaker, and a full page of 100K can come back flat and grayish. Adobe notes that standard 100% process black may not look completely opaque when it overprints other colors, so inks underneath can show through slightly. To prevent that in large black areas or large black type, Adobe points to a four-color rich black, with the exact percentages from your printer.

Why does black look different on screen than in print?

Your screen may be flattering the black. Illustrator and InDesign both have an Appearance of Black preference that controls how 100K looks on screen and on RGB output. It's often set to show all blacks as rich black, and then 100K looks deeper on screen than it will print. Check yours.

In InDesign the setting is under Edit > Preferences > Appearance of Black on Windows, or InDesign > Preferences > Appearance of Black on a Mac. Illustrator has a preference with the same name. Set it to display all blacks accurately while you work, so 100K and rich black look different on screen the way they will on paper.

Adobe describes this as a setting for RGB devices, so it changes what you see, not the color plates that go to press. For which program suits which print job, see Illustrator vs Photoshop vs InDesign.

What happens to RGB black when a file is converted to CMYK?

RGB black (0/0/0) does not turn into 100K. In a test conversion of sRGB black to the U.S. Web Coated (SWOP) v2 profile, it came out at roughly 75/68/67/90, close to 300% total ink. The exact numbers shift with the profile and conversion settings, but you usually end up with a mix of all four inks, not clean 100K.

Bookmobile notes that converting RGB black to CMYK "creates a rich mix." That's a problem for small type. Black text that started as RGB will print in four inks, with the registration risk covered below. After converting, select your text and fine lines and set them to the 100K swatch.

What is rich black, and which build should you use?

Rich black is 100K with cyan, magenta and yellow added underneath, so large areas print deeper and more solid. Here's what three printers publish:

• 4over4: its FAQ gives C50 M40 Y40 K100 as a common recipe for a deep, neutral black.
• Jukebox Print: 60/40/40/100, for large solid black areas and for text over 16 pt.
• Bookmobile: 60c, 40m, 40y, 100k.

They're close but not the same, and other printers use other numbers. Ask yours and use its build.

The rhino poster below is the kind of layout where this choice matters. It's my SCF Typography coursework: a black rhino built from conservation words on a full black background, made in Illustrator and turned in as an 11 × 14 in print PDF with 0.125 in bleed. It was a class project, not commissioned by the International Rhino Foundation, and the logo belongs to the IRF. The black covers nearly the whole sheet, and hundreds of the words are small, so both sides of this guide apply to one file. The poster sizes guide covers the 11 × 14 format and bleed.

When should you stick with 100K black?

Use 100K for body text, small type, thin strokes, hairline rules and fine detail. Jukebox Print also recommends it for tints and gradients.

The reason is registration. A rich black prints on four plates, and if the plates land even slightly out of line, small black type picks up colored edges and looks soft. 100K prints on one plate, so its edges stay crisp. As 4over4 puts it: "keep thin type as straight 100% black."

InDesign helps here. By default it overprints the [Black] swatch at 100%, which prevents misregistration of small black text over colored backgrounds. The option is called Overprint [Black] Swatch at 100%, in the same Appearance of Black preferences. The same thinking applies to small text and thin lines in a logo. For which logo file to send where, see logo file types.

What is registration black, and why keep it out of artwork?

Registration is a special swatch that prints at 100% on every plate: 100/100/100/100 on a CMYK job, or 400% ink. It exists so crop marks and registration targets show up on every plate and the press operator can line them up.

On screen it looks like black, which is why it ends up in artwork by mistake. Adobe warns that using Registration on large areas causes excessive ink coverage, printing problems and wasted ink, and that it should not be confused with rich black.

What is total ink coverage, and why does it matter?

Total ink coverage is the sum of the four ink percentages at any spot. 100K is 100%. A 60/40/40/100 rich black is 240%. Too much ink on paper causes printing problems, and every press and paper has a limit.

Limits depend on the press and paper, and Adobe's help says to ask your print service provider for the maximum. Use your printer's number over any general figure.

You can check coverage before you send a file:

• InDesign: Window > Output > Separations Preview, then set View to Ink Limit. Areas over the limit show in red.
• Acrobat Pro: open Output Preview in the Print Production tools and turn on Total Area Coverage with your printer's limit. Adobe's Output Preview help page walks through it.

PDF/X export and Acrobat preflight are among my print production skills. A check like this is a good place to catch a stray RGB black or Registration swatch before the file goes out.

If you'd like a poster or other print piece set up with the right blacks from the start, see poster design. The FAQ answers common questions, including starting prices.