Surface guide
QR codes on invitations and greeting cards
An invitation QR code is read at arm's length so 2 cm is enough. The design pressure is the opposite of usual — the risk is a code so heavily styled or foiled that it no longer scans.
| Typical scan distance | 20–30 cm |
|---|---|
| Minimum code width | 2–2.5 cm |
| Error correction | M |
Foil and letterpress do not work
- Foil has no reliable luminance contrast; a camera sees a bright reflective patch, not dark modules.
- Letterpress deboss creates shadows at module edges that shift the threshold.
- Dark ink on a dark card fails even when it looks fine to the eye — the decoder works on luminance, not on how deliberate the palette looks.
Print the code in a dark ink on a light panel, even if that panel is a small light rectangle set into a dark design.
What to encode
- RSVP form — the highest-value use, because it removes a postal round trip.
- Calendar event so the date lands in the phone.
- Location pinned at the actual entrance, not the postcode centroid.
- A wedding website with directions, accommodation and gift list.
A social hub style page holding all of these behind one code is usually better than three codes on one card.
Longevity
People keep invitations. If the linked page is taken down after the event, the code becomes a dead link in someone's keepsake box. Leave a simple page in place.