Surface guide
QR codes on shipping labels
Shipping label QR codes are scanned close, often by handheld imagers rather than phones, and often after the parcel has been through a conveyor. Error correction Q and a thermal-transfer ribbon are the two decisions that matter.
| Typical scan distance | 10–30 cm |
|---|---|
| Minimum code width | 1.5–3 cm |
| Error correction | Q |
Direct thermal is the wrong choice for anything slow
Direct thermal labels fade from heat, sunlight and abrasion. A parcel sitting in a van in summer can lose enough contrast in a day to fail. Thermal transfer with a wax-resin ribbon survives the journey.
Scanner type changes the rules
Handheld 2D imagers read far more forgivingly than phone cameras — better optics, controlled illumination, and a decoder tuned for damaged codes. If your codes are read by warehouse hardware, you can go smaller than the phone-based rules suggest. If a courier might scan with a phone, use the phone rules.
Placement
- Never across a box edge or a seam. Flat surface only.
- At least 10 mm from the label edge — applicators drift.
- Do not cover with packing tape. Tape adds a specular layer, and a wrinkle in it destroys local contrast.
- Keep clear of the shipping barcode's own quiet zone.
Data
Encode an id you resolve server-side rather than a long descriptive URL. Shorter payload, lower version, larger modules, better read rate on a scuffed label.