Custom QR code design: color, logo, and shape tips

A custom QR code design swaps black for brand colors, adds a logo, reshapes the dots, or wraps the code in a frame, and the code still scans when each change stays inside a limit. The limits are dark modules on a light background, a logo that stays inside the repair budget, modules large enough to print, and a blank margin of 4 modules.

What is a custom QR code design?

Error correction, the extra data every QR code carries to rebuild parts that are dirty, damaged, or covered, is the reason a restyled code still scans. A custom design is an ordinary code with brand colors instead of black, a logo in the middle, rounded modules, or a frame with a call to action. Each of those changes spends some of the repair capacity or leans on the scanner's tolerance.

Error correction has 4 levels, L, M, Q and H, and the level is fixed when the code is generated. A higher level repairs more, but the repair data takes space too, so the same content produces a bigger code. DENSO WAVE says Level M (15%) is the level selected most frequently.

A module is the smallest square that makes up a QR code, and the whole code is a grid of them. Color changes the contrast the camera depends on, a logo hides modules outright, and unusual dot styles make each module harder to read when it is printed small. That gives four limits to respect: color, logo, dot size, and margin.

Which colors keep a branded QR code scannable?

Dark modules on a light background stay readable because the scanner needs a strong difference in reflected light between the two. DENSO WAVE says QR Code scanners use red light to capture the image, so a red code on a white background cannot be read, and neither can a blue code on a green background. Its basic advice is to print black on white, and the darkest shade of a brand palette is the one to give the modules.

Phone cameras are a separate question. DENSO WAVE directs questions about reading with mobile phones to the carriers or manufacturers, and says that how well a phone reads a code depends in many cases on its camera. A printed proof scanned on real phones settles what a table of rules cannot.

Color pairings and what DENSO WAVE says about them

Modules	Background	Result
Black	White	DENSO WAVE's basic advice
Navy	White	Dark on light, so the same rule applies
Dark green	White	Dark on light, so the same rule applies
Red	White	Cannot be read
Blue	Green	Cannot be read

These rules follow from the contrast logic and cover gradients and photo backgrounds, which DENSO WAVE does not address directly. They are editorial advice, not DENSO WAVE requirements:

• Make the modules darker than the background, never the other way round.
• Keep a gradient inside dark tones, so no part of the code fades toward the background.
• Put a solid light backing behind the code when it sits on a photo or pattern.

If red is the main brand color, use it in the frame around the code rather than in the modules. The frame sits outside the code, so it leaves the contrast the scanner relies on untouched.

Logo size and error correction in a QR code with logo

Whatever sits on top of the modules counts as damage to the scanner, so every bit of overlay draws on the repair data the code carries. DENSO WAVE measures that repair capacity in codewords, the units a code's data is built from. In its worked example, the code pairs data codewords with an equal number of Reed-Solomon codewords and can correct a quarter of the total, which is 25%, the rate of Level Q.

DENSO WAVE worked example: codewords in one code

Codewords	Count
Data	100
Reed-Solomon	100
All together	200
Correctable	50

Those percentages are not a logo allowance. Whatever a logo uses is gone before a scratch, a fold, or glare adds its own damage, and DENSO WAVE warns that a deformed code can fail on even a tiny missing or smeared part, or respond slowly. DENSO WAVE also suggests Level Q or H for a dirty setting such as a factory floor, and Level L only for a clean one with a lot of data.

A logo's width and the area it covers are different numbers, because area grows with the square of the width. The table gives the calculated area for three logo widths. For a code with a logo, choose a higher level than a plain code needs, keep the logo near the narrow end of the table, and scan the proof before anything is printed.

Logo width and the share of the code area it covers (%)

Logo width	Area covered
15	2.25
20	4
30	9

Which QR code shapes still scan reliably?

Dot style stays a matter of looks until the modules get too small to print, and the limit comes from how much of each square the style leaves filled. On a common laser printer, DENSO WAVE puts the minimum printable module size at about 0.17 mm. A style that fills less of each square reaches that floor sooner than a plain square does.

The three large squares in the corners, the finder patterns, tell the camera where the code is and which way up it sits. A circle inscribed in a square module fills about 78.5% of it, and a diamond fills 50%, so the table shows why circles and diamonds ask for a larger print than squares do.

Share of each module that a dot style fills (%)

Dot style	Fill
Square	100
Circle	78.5
Diamond	50

For a code printed small, square modules are the safe choice. Circles and diamonds suit codes printed large, where each module is still well above the printer floor.

The smallest code has 21 x 21 modules, so at 0.17 mm per module it cannot be smaller than about 3.57 mm. That is the floor a printer sets, not a size a phone reads from arm's length. For sizes that work at real scanning distances, see QR code minimum size: how small can it be?.

Frames and CTA text for a custom QR code

Anything placed on top of the modules, or inside the blank margin around them, risks a failed read, so decoration goes outside both. DENSO WAVE warns that laying an illustration or design over a code can stop it reading or slow the response, and asks to be consulted beforehand about designs that involve one. A frame leaves the modules untouched.

The quiet zone is the blank margin of 4 modules that DENSO WAVE says a code needs around it in actual use. Measure it in modules, so it grows with the code, and start the frame's inner edge beyond it. The call-to-action (CTA) text goes in the frame's own band, above or below the code.

A bare code gives a scanner no reason to stop, so the CTA names what the scan delivers. A few short examples by placement:

• "Scan for the menu" on a table stand
• "Scan to get your coupon" on a shelf tag
• "Scan to check in" on an event ticket
• "Scan for English" on multilingual signage

Coupons and check-ins usually need scan counts, which takes a dynamic code whose link can change after printing. For the difference, see What is a dynamic QR code? Static vs dynamic.

Minimum size, paper and proof testing for a personalized QR code

Printed width is the module count multiplied by the module width, so more data packs more modules into the same space and shrinks each one. DENSO WAVE's example is Version 2, which has 25 x 25 modules: at 0.5 mm per module the code measures 12.5 x 12.5 mm, before the quiet zone. Each version step up adds 4 modules per side, up to Version 40.

A higher correction level also enlarges the code, so a long link and a logo both push the modules smaller at the same printed width. Export the largest image available and place it at its final size, because stretching a small raster image blurs the module edges. For where to put the code on flyers and posters, see QR Code Flyer Size and Placement: The 10:1 Rule.

Shine is the other print risk. DENSO WAVE says glistening on vinyl or similar transparent material may interfere with reading, and its fix is to print a white background under the code.

Because a phone's reading ability depends in many cases on its camera, a code that scans on one phone proves little. A short test covers the gap:

1. Print a proof at the final size, on the final paper or material.
2. Scan it with the built-in camera app on at least one iPhone and one Android phone.
3. Hold each phone at the distance people will actually stand.
4. Try it under the lighting where the code will hang, including any glare.
5. Open the link each time and confirm it lands on the right page.

Summary: the limits to check before you publish

A custom QR code design scans when color, logo, dots, and margin all stay inside their limits, and a printed proof confirms it. The table puts each limit next to the habit that breaks it.

What to do and what to avoid before printing

Do	Don't
Dark modules on a light background, black on white when in doubt	Red modules on white, or blue on green
A higher correction level before adding a logo	A logo that uses up the whole repair budget
A blank margin of at least 4 modules on every side	A frame, CTA, or background touching that margin
Modules above the printer floor, and well above it for phones	Dot styles that fill little of each module in a small print
A white background under the code on transparent material	Glossy vinyl with no white backing
A printed proof scanned on more than one phone	A design checked only on screen

Two of these checks come after the design already looks finished, which makes them easy to skip. A frame added late in the layout can creep into the quiet zone, and a proof scanned only on the designer's own phone says little about other cameras.

If a printed code still won't scan, see QR code not scanning? Count the quiet zone first for the causes. To build a code with your own colors and logo, a QR code generator lets you test each choice on a phone before the file goes to print.