Everything we've learned building a QR generator — what makes a code scan reliably, what quietly breaks it, and how to get it right before you send anything to a printer.
Make a QR code that connects guests to your Wi-Fi with one scan. How the WIFI: format works, why special characters break most generators, and how to test it properly.
What L, M, Q and H actually do, how much damage each survives, and why the highest setting is usually the wrong choice. With real capacity figures from the ISO standard.
The 10:1 distance rule, minimum sizes for business cards, posters and billboards, why the quiet zone matters, and how to calculate the exact size you need.
When a raster PNG is fine and when you need vector SVG. What actually goes wrong when you scale a PNG, and why printers ask for vector files.
Sizing, placement, lighting and the mistakes that cost restaurants covers. What to link to, why static codes have a catch, and how to test before printing table cards.
How contact QR codes work, why a full vCard often makes a code too dense to scan, and when to link to a contact page instead.