How-to guides
How to put a QR code on a mug
On a standard 11 oz mug (about 26 cm circumference) keep the code at 4 cm or less — roughly a sixth of the circumference — so curvature doesn't fold the grid away from the camera. Use dye sublimation or a fired ceramic decal if the mug will meet a dishwasher.
The curvature budget
A mug is a cylinder, and a camera can only read modules it can see squarely. As the code wraps around the curve, modules foreshorten until the far edges become slivers. The working rule from curved-surface printing: keep the code's width to about 1/6 of the circumference — roughly a 60° arc, where the outermost modules are still only about 13% narrower to the camera.
For the standard 11 oz mug (about 8.2 cm diameter, 26 cm circumference) that caps the code at about 4.3 cm wide. Height is unconstrained by curvature, but keep the code square — so ~4 × 4 cm is the practical ceiling, and 3.5 cm with generous quiet zone is comfortable.
Is 4 cm enough? Under the 10:1 rule it scans from 40 cm — a mug on a desk or held in a hand, which is exactly how mugs are scanned. Run your payload through the size calculator; keep it short so the version stays low and modules stay chunky at 4 cm.
Print methods, honestly compared
| Method | Dishwasher | Notes |
|---|---|---|
| Dye sublimation | Good (with proper coating) | The standard for custom mugs; dye bonds into the polymer coating. Quality of the blank's coating decides longevity |
| Fired ceramic decal | Excellent | The most durable option — the image is fused into the glaze. Costs more, minimums higher |
| Vinyl sticker/decal | Hand-wash only | Fine for events and short-term; edges lift with heat and detergent |
| Direct UV print | Moderate | Sharp, but abrasion and dishwashing wear the surface print |
If the mug is a gift or merch that will live in someone's kitchen, assume it meets a dishwasher weekly — the failure modes are detailed in QR codes that survive dishwashers. A code that flakes into unreadability in three months is worse than no code.
Placement
- Either side works; think about the resting state. Mugs get scanned sitting on a desk, so the code should be visible without picking the mug up and hunting.
- Keep the code and its quiet zone clear of the handle — the handle root distorts the printable area and shadows the edge modules.
- Vertically: centred, not near the rim (glaze rounds off) or the base.
- Dark modules on the glaze's white; if the mug is coloured, reserve a white panel.
Practical uses that fit the 4 cm ceiling nicely: a WiFi code on café and office mugs (guests scan the mug in front of them — a natural fit for cafés), a short URL to a menu, portfolio or team page. The full surface spec is in QR codes on mugs.
Before you order 50
Order one. Scan it on the desk and in hand, under kitchen and office lighting, with more than one phone. Put it through five dishwasher cycles and scan again. Then verify the payload with the validator and place the batch order. The full protocol is in testing before printing.
FAQ
How big can a QR code be on a mug?
About a sixth of the circumference before curvature starts hiding modules — roughly 4 cm wide on a standard 11 oz mug. That scans comfortably from desk distance with a short payload.
Will a QR code on a mug survive the dishwasher?
Only with the right process. Dye sublimation on a properly coated blank holds up well; fired ceramic decals are effectively permanent; vinyl decals are hand-wash only and will lift.
Where should the QR code go on a mug?
Centred vertically, well clear of the handle and its quiet zone, positioned so it faces outward when the mug rests naturally on a desk. Either side of the handle works.
Why won't my mug QR code scan?
Usually curvature — the code is too wide for the cylinder and edge modules foreshorten — or a payload too long, making modules tiny at 4 cm. Shorten the URL, shrink the code's width, and rescan.
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Related
- How to put a QR code on a t-shirt — Screen print or vinyl beat DTG for QR edges. At least 10 cm on the chest, dark modules on a light panel, and test the shirt worn — fabric drape distorts codes.
- QR codes on curved surfaces — How much curvature a QR code tolerates, the one-sixth-of-circumference rule, and why orientation on a cylinder decides whether it scans.
- QR codes that survive dishwashers — Which mug and glassware marking processes survive dishwasher cycles — fired ceramic decals, etched infill, sublimation — and a 20-cycle test protocol.
- How to test a QR code before printing — Verify it decodes, check the payload character by character, print at final size, scan with old phones in bad light, and probe the damage margin. A checklist.