Print a QR that scans the first time.
A QR is a piece of math, not a graphic. Get the spec right and it scans from across the parking lot. Get it wrong and your customer is angry by the time you find out. This is the spec.
Last updated · May 2026 · v2.4
If you only read one section, read this.
These six rules cover ninety percent of the print failures we see. If your QR is following all six, it'll scan.
Minimum size
Print the QR at least 1 inch square (25mm) for arm's-length scanning. Smaller and a phone camera can't resolve the modules.
1 inch minimum · arm's lengthQuiet zone
Leave a clear margin around the QR. White space, ≥4 modules wide. Without it, the camera can't find the edges.
4 modules · all four sidesError correction
Use Q level (25% recovery) for all print. Bump to H (30%) when you've got a center logo or expect surface damage.
Q default · H with logoContrast
Dark on light, always. Contrast ratio ≥3:1 for scan reliability — but ≥4.5:1 if you also want WCAG AA. Never invert.
≥3:1 minimum · 4.5:1 idealColor profile
Convert to CMYK before sending. Print in 100K (black ink only) for the modules — RGB blacks on press come out muddy and can fail scan.
CMYK · 100K modulesCurved surfaces
Wrapping a QR on a bottle, mug, or cylinder? Size up by 25% and keep the QR within ±15° of camera-perpendicular when scanning.
+25% size on curvesWhat's actually in there.
A QR isn't a picture, it's a coordinate system. These regions are non-negotiable — knowing what they do helps you decide what to leave alone.
The three corner squares
Top-left, top-right, bottom-left. The phone uses these to find the QR and figure out its rotation. Never crop or alter them.
Bottom-right square
Helps the phone correct for perspective skew. Smaller QRs (under v2) skip this — but anything print-sized has it.
The blank margin
4 modules of empty space all the way around. Don't put text or graphics in here, even if it looks empty. The camera needs the gap.
Bottom-right square
Helps the phone correct for perspective skew when the QR is photographed at an angle. Crucial for surface scanning.
Center · ≤25% area
If you put a logo in the center, error correction H can recover up to 30%. We cap the visual logo at 25% area to leave a safety margin.
Everything else
The actual encoded data (top half) and error-correction parity (bottom half). Touching these breaks the QR — but error correction means you can lose up to 30% and still scan.
Bigger is always safer.
A QR is sized by its scan distance, not its surface area. Use this table to size up correctly — undersize is the #1 print failure.
| Scan distance | Min size | Recommended | Use case |
|---|---|---|---|
1 ft ~30cm · arm's length | 1in 25mm | 1.2 in (30mm) | Restaurant menu · product packaging · business card |
6 ft ~2m · standing back | 2in 50mm | 2.4 in (60mm) | Storefront window · gallery wall · trade show booth |
20 ft ~6m · across a room | 8in 200mm | 10 in (250mm) | Bus stop ad · conference signage · museum placard |
50 ft ~15m · across a parking lot | 18in 450mm | 24 in (600mm) | Billboard · building facade · outdoor banner |
Three rectangles that decide whether your QR survives the cutting blade.
Set up your file with three nested rectangles.
Print runs cut through paper unevenly. The bleed protects the design when the cut wanders by 1–2mm. The safe zone protects the QR from being cropped by a wandering cut. Get the ordering wrong and the trim line can clip the modules.
Bleed3mm beyond trim — for the printer to cut through. Background color extends to here, not the QR.
Trim lineat edge — the dashed cut. The QR's quiet zone starts here, not earlier.
Safe zone5mm inside trim — QR + quiet zone live entirely inside this. Safe from any cutting blade wander.
Pick a level. Q is the print default.
QR codes have built-in redundancy via Reed-Solomon error correction. Higher level = bigger QR but more damage tolerance. For print, you almost always want Q.
Low
Smallest file, lowest tolerance. Use for screen-only display where the QR will be perfect.
When · screen UI only
Medium
Default for digital. OK for clean print on glossy paper, but risky if you might add a logo later.
When · digital + logo-free print
Quartile
QRBliss default for all print exports. Tolerates ink smudges, fingerprints, light scuffing. Recommended for menus and packaging.
When · any print without logo
High
For QRs with center logos or in heavy-wear environments (table tents, outdoor signage, fabric). Bigger QR, but worth it.
When · logo + outdoor
Dark on light. Always.
A QR is a contrast pattern. The phone camera doesn't see the color — it sees the brightness difference. Inverting (light on dark) doesn't always work; gradient and photographic backgrounds break scanning.
What works
What breaks
8 things to verify before you send to the printer.
Tap each one as you check it off. If you can't check all eight, don't send the file yet.
Pre-print verification
Does this all check out? Then you're good to ship.
Pick the right export.
QRBliss exports PNG, SVG, and PDF. Each has a use — and one usually-fatal anti-pattern.
| Format | Best for | Resolution | Gotcha |
|---|---|---|---|
| PNG | Web · email · Slack raster bitmap | 4096 × 4096 px | Don't use for print. PNG looks fine on screen but pixels at any size large enough to scan. |
| SVG | Designer handoff · web vector, infinitely scalable | vector | Best web option. Renders crisp at any size. Pass to a designer if they want to compose with it. |
Print, every time vector + 3mm bleed + CMYK | vector | Default for any printer. Includes bleed, quiet zone, and CMYK color profile pre-baked. Send as-is. |
Edge cases we get asked about.
Got a weird substrate?
Embossed leather, holographic foil, fabric — we've probably tested it. Send a sample photo and we'll tell you what specs to use.
print@qrbliss.comCan a QR be round, or have rounded corners?
The three finder squares in the corners must stay sharp-cornered — that's how the camera locates the QR. The data modules in the middle can be rounded (“dot-style”) without breaking scanning. QRBliss's “Rounded” template does exactly this. Truly round QRs (circular outline + circular modules) tend to fail under low light.
What about transparent backgrounds?
Risky. The QR's quiet zone needs to be a clear, flat color — transparent over a busy background fails. If you must overlay on photography, place the QR on a solid white (or solid dark) tile with at least 4 modules of margin around it. The PDF export bakes a quiet-zone tile by default; PNG can be transparent but you'll need to add the tile yourself.
Can I embroider a QR onto fabric?
Yes — with caveats. Use error correction H (30%) and size up to 2 inches minimum. Stitch density matters: too sparse and the modules bleed into each other; too dense and the fabric warps. Test-stitch one before committing to a run. The classic-square template (not rounded, not dotted) is most embroidery-friendly.
Will it scan through a glass storefront window?
Usually yes. Glare and reflections are the failure mode. Print on matte adhesive vinyl, not glossy. Mount the QR slightly below eye-level so daylight reflections don't wash it out. Size for the actual scan distance — if the QR is on the inside of the window and you scan from the sidewalk, that's at least 6 ft, so use the 2-inch sizing.
Can I print a QR on a dark or black background?
Inverted (light modules on dark bg) is risky — some older Android cameras can't handle it, and it fails about 8% of the time in our scan tests. If your design demands dark, the safe move is a dark frame around a normal-orientation QR on a white tile. The white tile is the quiet zone. The dark frame is decorative. The QR scans every time.
Print-ready in 60 seconds.
QRBliss exports already follow this spec. Drop your URL, pick a template, hit Export PDF — the bleed, quiet zone, color profile, and EC level are all baked in.