Best Practices for Printing QR Codes
The core checklist: use SVG for anything getting resized, keep strong dark-on-light contrast, size for the expected scan distance (roughly 2×2 cm minimum for close-range), preserve the quiet-zone margin, and always test-scan a physical print before running a full batch.
Two mistakes account for most print failures: shrinking a code below what the scanning distance allows, and cropping too close to the code (removing the quiet zone). Both are invisible on a screen preview and only show up once ink is on paper — which is exactly why a single test print, scanned with two or three different phones, is worth doing before a large print run.
This site's generator defaults to error correction level H (~30% damage tolerance) specifically for print use, giving extra headroom against ink bleed, folds, or minor smudging.