QR centre labels
A QR Label is great for phones but useless for human eyes — you can't tell two stickers apart at a glance. The centre label feature solves this by overlaying a short readable text in the middle of the QR. Up to four characters: K1, K2, B7, AB12.
QR Labels have built-in error correction, so up to about 30% of the visible area can be obscured (with our error-correction level set to High) and the code still scans. Putting a small label in the centre uses about 8% of the area — well within tolerance.
Setting a centre label
On the QR Labels page (/qr/), each card has a thumbnail of the QR. Click the card to open the print page, where there's a small input field labelled Centre label. Type up to 4 characters. Hit Save.
The label is now baked into the QR thumbnail and the print output. Re-print the sticker if you've already printed without a label.
You can change the centre label at any time without rotating the underlying token. The token is still the same; only the rendered overlay changes.
A useful labelling scheme
Most users invent their own scheme. Some patterns that work:
- Room + number. K1 through K9 for kitchen boxes, B1 through B9 for bedroom boxes.
- Type + number. I1 through I99 for individual items, B1 through B30 for boxes.
- Custom code. DAD for things from your dad's storage. MOVE24 for things being moved in 2024.
Whatever you pick, write down the meaning somewhere — not in your head. Future-you doesn't remember why "K7" is in the bedroom.
When centre labels matter
- Visual scanning. You can see B7 across a storage unit and grab the right box without scanning every sticker.
- Print sheets. When you print 21 stickers on a sheet, the centre labels are how you tell them apart at a glance.
- Photographing boxes. When you take a photo of a stack of boxes, the centre labels are readable in the photo.
When centre labels don't matter
- One-off scans. If you only ever scan with your phone, the centre label is decoration.
- Single QR per object. A unique high-value item probably doesn't need a centre label — its photo is enough to identify it.
Character set
Centre labels can use uppercase A-Z, lowercase a-z, and digits 0-9. Up to 4 characters. We don't allow special characters because some printers render them badly at small sizes.