Surface guide
QR codes on stickers
Sticker QR codes are usually scanned close, so 1.5–4 cm is enough, but stickers get scuffed, curled and rained on, which is why error-correction level Q is the sensible default here rather than M.
| Typical scan distance | 15–40 cm |
|---|---|
| Minimum code width | 1.5–4 cm |
| Error correction | Q |
Why Q rather than M
A sticker's failure modes are physical: a corner peels, a thumb rubs the surface, grit scratches it, UV fades the ink. Level Q tolerates about 25% damage against M's 15%, and on a small code the extra version costs little.
Do not jump to H reflexively. It may push the version up two steps, shrinking every module and making the code harder to scan when clean.
Material choices
| Material | Life outdoors | Notes |
|---|---|---|
| Paper | weeks | Indoor only; ink runs |
| Vinyl (monomeric) | 1–3 years | Flat surfaces |
| Vinyl (cast/polymeric) | 5–7 years | Conforms to curves |
| Polyester | 5+ years | Chemical and heat resistant |
| Polypropylene | 2–4 years | Good for bottles and tubs |
Matt laminate for anything scanned in daylight or under lighting; gloss laminate causes the same specular failure as gloss paper.
Curved surfaces
On a bottle or a tube, keep the code within about a third of the circumference. Beyond that, the curvature at the edges exceeds what the alignment patterns can correct, and a code below version 2 has no alignment patterns at all.