1. Distance Math
Visitors usually scan from 1 to 3 meters. At the 10:1 rule from our [QR size calculator](/qr-size-calculator), that means 10 to 30 cm. Crowded halls and poor lighting justify the conservative 8:1 ratio, so budget 15 to 40 cm.
2. Placement
* Position the code between chest and eye level (about 120 to 160 cm from the floor).
* Keep it away from the bottom third, where people block it.
* Leave a clear quiet zone; do not overlap it with graphics—review our [QR placement guide](/qr-placement-guide).
* Test visibility with a [QR scanner](/qr-scanner) from the intended viewing distance.
3. Call to Action
State what the scan delivers ("Scan for the 2-minute demo"). Large banners also help to include a short typed URL as a fallback. Generate trackable short URLs with our [UTM builder](/utm-builder). Before printing, verify scan quality using our [printed QR tester](/printed-qr-tester) on the actual banner material.
4. Printing
Use vector files at the finished banner size and matte material to limit glare from booth lighting. Generate high-quality codes with our [URL QR code generator](/url-qr-code-generator). For understanding how error correction affects large format prints, use our [error correction simulator](/error-correction-simulator).
Putting this into practice
Start with the smallest real test you can run. Generate the code, print it at the exact size you plan to use, and scan it with two different phones in the lighting where it will live. Check that the destination page loads quickly on a mobile connection and that the call to action next to the code tells people what they will get. If anything feels slow or unclear, fix it before you print a full batch, because reprints cost more than a short test. Keep a note of the size, material, and placement that worked so the next batch starts from a proven setup.
Common mistakes to avoid
The most common mistakes are easy to avoid once you know them. Long payloads make modules tiny, low contrast makes edges hard to read, and text placed too close to the border eats the quiet zone the scanner needs. Covering a corner finder pattern with a logo or a sticker breaks detection entirely, and a code placed behind glare or on a curved surface fails even when the print is perfect. Review each of these points on a proof copy, and treat any failure as a reason to adjust the design rather than a reason to blame the scanner.
Quick checklist
- Keep the payload as short as practical so modules stay large.
- Keep dark modules on a light background with strong contrast.
- Leave a clear quiet zone on all four sides of the symbol.
- Test the printed code at the real viewing distance and lighting.
- Confirm the destination page loads fast on a phone.
- Recheck the code after any change to the link, design, or placement.
