The rule
Code width should be at least one tenth of the distance it will be scanned from. A table card read from 30 cm wants 3 cm; a shop window read from the pavement at 2 m wants 20 cm. That rule assumes a normal code of 25 to 29 modules. Denser codes need more.
Sizes by use
| Where | Typical distance | Minimum width | Comfortable |
|---|---|---|---|
| Business card, label | 15 to 25 cm | 2 cm | 2.5 cm |
| Menu, table tent, receipt | 30 to 50 cm | 3 cm | 4 cm |
| Flyer, brochure, packaging | 30 to 60 cm | 3 cm | 4 to 5 cm |
| A4 poster, notice board | 1 to 1.5 m | 10 cm | 12 cm |
| Shop window, roll-up banner | 2 to 3 m | 20 cm | 25 cm |
| Vehicle, billboard | 5 m and more | 50 cm | 1 m |
| Picture code (any use) | as above | add 50 percent | double |
Module size, the number printers care about
A code is a grid of modules; the physical size of one module decides whether a camera can separate them. Aim for 0.5 mm per module or more. A 25-module code at 2 cm gives 0.8 mm modules (fine). A 45-module vCard at 2 cm gives 0.44 mm (marginal). The same vCard at 3 cm gives 0.67 mm (fine). Shorter content, fewer modules, smaller print.
Our generator reports the module count indirectly: shorter links produce visibly simpler codes. A link of 30 characters at error correction M is 25 modules; 60 characters is 29 to 33; a full vCard is 41 to 49.
Quiet zone and bleed
Leave a clear margin around the code of at least two modules (the standard says four). On a business card keep the code and its margin inside the safe area, 3 mm from the trim; a code in the bleed gets guillotined. The margin setting in the generator adds this space into the file so it survives layout.
Which file to give the printer
SVG: vector, any size, the right answer for anything printed professionally.
PDF: use the generator’s PDF export with the width in millimetres when the print shop insists on PDF or wants an exact size.
PNG: screens, Word documents, Canva. For print, 2048 px or more and never upscaled.
Avoid JPEG for codes: compression artefacts soften the edges.
Surfaces
Matte paper, card and vinyl scan best. Gloss laminate, glass and metal cause glare; if you must, print bigger and keep contrast at black on white. Textured stock (linen, kraft) is fine at 3 cm and up. Fabric and embroidery need large modules, 2 mm or more, and a simple square design.