Starting sizes by use
| Where it goes | Scanned from about | Starting size |
|---|---|---|
| Business card | 20 to 30 cm (8 to 12 in) | At least 2 cm (0.8 in) square; 2.5 cm if you can |
| Sticker on a laptop, window or box | 30 to 50 cm (12 to 20 in) | 3 to 4 cm (1.2 to 1.6 in) |
| Counter or table card | 50 cm to 1 m (20 to 40 in) | 5 to 8 cm (2 to 3 in) |
| Poster or door sign | 1 to 2 m (3 to 6 ft) | 10 to 20 cm (4 to 8 in) |
These are rules of thumb built on the idea that a code should be about one tenth of the distance it is scanned from. Always test a printed proof.
Why a code fails when it is too small
A QR code is a grid of small squares called modules. A phone camera has to resolve each module. The more characters the code holds, the more modules it has and the smaller each one is at a given print size. So a short link can be printed smaller than a long link, and a full contact record (see what a vCard is) needs a much larger code than a short web address.
That is why a code that points to a short link, like NearvoQ's card codes, prints cleanly at business-card size, and why a dynamic code is easier to keep small: the data in the code stays the same however the destination changes. Static vs dynamic QR codes explains the difference.
A four-step test before you print a batch
Print one proof at final size
Use the same paper and finish as the batch. Glossy and textured stocks scan differently from matte.
Scan at the real distance
Hold a phone where a customer would: about the length of your forearm for a card, farther for a sign.
Try several phones and light
An older phone, a newer phone, dim light, and a bit of glare from a window or lamp.
Make it larger if any scan is slow
If any phone hesitates for more than a second or two, increase the size or shorten the link.
Keep it scannable
- Leave a blank margin of at least four modules on every side.
- Use dark squares on a plain light background, never inverted.
- Do not stretch the code or squeeze it into a corner.
- Avoid folds, foil and glossy patches under the code.
- Add a short label so people know why to scan; see putting a QR code on a business card.
