Friday Print Tips: Getting Black Right in CMYK – Why Your “Black” Prints Grey

You design a piece with a big, dramatic black background.On screen it looks deep and inky.In print it comes back… charcoal.

In most cases, nothing “went wrong” on press. That’s just what happens when you treat black on screen (RGB) and black on paper (CMYK) as if they’re the same thing.

If you remember one rule from this post, make it this: Use K-only black for small text, a controlled rich black for big areas – and never use registration black in your design.

Why “100% K” often looks like dark grey

In CMYK, a “pure” black swatch is usually C0 M0 Y0 K100 – 100% black ink, no cyan, magenta or yellow.

On paper, that often prints as a very dark grey, not a deep, velvety black. Paper reflects more light back through that single layer of black ink than your monitor does. On screen, “black” is made with light; in print it’s made with ink.

That’s why we use rich black.

What is rich black?

Rich black is still black, but instead of only using K (black ink), it uses a combination of all four process inks – cyan, magenta, yellow and black.

A typical neutral rich black formula might look like:

• C60 M40 Y40 K100

You don’t need that exact mix; the point is the structure:

• Some CMY underneath

• 100% K on top

That gives you a deeper, more saturated black and smoother coverage in large solid areas.

Every print shop has its own preferred values for rich black, tuned to their presses, inks and papers. Treat any numbers as a good starting point, not a universal recipe.

When to use rich black vs plain black

The goal is not to use rich black everywhere. In the wrong place, it can cause more problems than it solves.

Use rich black for:

• Large solid backgrounds

• Heavy colour bands and big blocks of black

• Big headings and display type

• Covers, presentation folders, high-end brochures where depth matters

Here, a K-only black tends to look flat and a little lifeless. Rich black gives you that “ink well” depth.

Use K-only black (0/0/0/100) for:

• Body text and small copy

• Fine rules and hairlines

• Barcodes, legal notes, small icons

If you build small text from four plates (rich black) instead of one (K-only), even tiny mis-registration on press can create coloured halos or softness around the letters. Using one clean K plate keeps small type sharp and readable.

Never use registration black

There’s a special swatch in design software called Registration or “Registration black.” It’s usually 100/100/100/100 – all four inks at 100%.

It exists for printers to align plates and marks. It does not exist for design work.

If you use registration black in your artwork you can end up with:

• Too much total ink on the sheet

• Drying issues and smudging

• Show-through on thinner stocks

• Muddy, dirty-looking blacks instead of clean depth

Bottom line:Use rich black for big areas, K-only for small text, and never touch registration black in your layout.

Practical setup in your design software

You don’t need to become a prepress operator. Just define two black swatches and be consistent.

In InDesign / Illustrator (and similar tools)

Create these swatches:

• Body Black – C0 M0 Y0 K100

  • Use for paragraph styles, small logos, footnotes, hairlines.

• Rich Background Black – e.g. C60 M40 Y40 K100

  • Use for large backgrounds, big headings, cover panels.

Make them global swatches so you can adjust them in one place if needed.

Then update your styles:

• Assign Body Black to all body text and small labels.

• Assign Rich Background Black to large display elements and backgrounds where you want depth.

In Canva and other RGB-first tools

Canva doesn’t give you full CMYK control, but you can still make things better:

• Choose one “brand black” colour and use it consistently for text.

• Do a test export to a PDF Print file, then ask your printer to check how that black converts to CMYK.

• If you need a deeper black background, work with your printer to test one rich black value and stick to it for future jobs.

The key is consistency, not guessing a new black every project.

A simple black checklist before you export

Before you send any job to print, run through this quick checklist:

• Are small text and fine lines set to K-only black, not a four-colour mix?

• Are large solid areas using one consistent rich black formula?

• Are you avoiding registration black entirely in your artwork?

• Are all blacks intended to look the same actually using the same swatch?

If you can answer “yes” to those questions, you’ve removed most of the common black-related surprises on press.

How we handle black at CETTEC

At CETTEC Printing, we use a house rich black formula tuned to our presses and papers, and we separate black usage like this:

• K-only black for small text, fine details and barcodes

• Rich black for large solid areas, backgrounds and big display type

• Controlled total ink so you get depth without drying problems or muddy edges

If you’re not sure how your blacks are built in your current artwork, send us your PDF and tell us where the important blacks are (backgrounds, big titles, body text). We’ll check the values, flag any risky builds, and suggest simple changes so your next “black” piece actually looks black when it comes off the press.