Surface guide
QR codes on name badges and lanyards
A badge QR code is scanned across a handshake — 30–50 cm — so 3–5 cm is right. The bigger issue is that lanyards swing and badges flip, so the code must be printed on both sides.
| Typical scan distance | 30–50 cm |
|---|---|
| Minimum code width | 3–5 cm |
| Error correction | M |
Print both sides
Badges rotate. A single-sided badge is unscannable half the time, and asking a stranger to turn their badge over is exactly the friction the code was supposed to remove.
Gloss pouches are the standard mistake
Most badge holders are glossy PVC. Under conference lighting they reflect, and the code inside becomes unreadable. Use matt pouches, or print directly onto the badge stock.
What to encode
| Payload | Good for |
|---|---|
| vCard / MeCard | Peer-to-peer contact exchange |
| URL to an attendee profile | Richer, updatable, and measurable |
| Opaque attendee id | Session check-in, lead scanning |
A URL is usually best: it is a short payload (so a coarse, easily scanned code), it can be updated, and it lets the attendee control what is shared. Encoding a full vCard puts personal data permanently into a pattern anyone can photograph across a room — worth a thought before printing a thousand.
Session scanning
If badges are scanned at doors by handheld readers, keep the payload to a short opaque id. Fast to decode, nothing personal on the badge.