QR codes explained: when to use them and how to make them scan

A QR code is a compact 2D barcode. Static codes encode text or a URL directly in the pattern — there is no account behind them, and they do not expire on their own. That simplicity is the point: print once, scan forever, as long as the destination still works and the print stays readable.

Good uses

• Menus, posters, and packaging that open a product or booking page
• Wi‑Fi join strings or event check-in links (keep destinations HTTPS)
• Business cards that open a portfolio or contact page
• Packaging that deep-links to instructions, warranty, or refill pages

Avoid encoding secrets you would not put on a public poster. Anyone who can photograph the code can read the payload.

Static codes vs short links you control

A static QR encodes the payload in the pattern. There is no GenShelf account in the middle, and the image does not “expire.” That is a feature: the code keeps working if this website goes down. It is also a constraint: if you print a campaign URL you do not control, you cannot retarget later. For posters and packaging you might reprint, encode a short URL on a domain you own and redirect. For a one-off Wi‑Fi join string or a business card you will reprint anyway, encoding the destination directly is simpler.

Never encode passwords, private event tokens, or internal admin URLs. Anyone with a camera can read a static code. If the destination needs login, that is fine — the QR should only open the public door, not carry the key.

Make scans reliable

1. Keep strong contrast — dark modules on a light background work best. Light-on-dark can fail on some cameras.
2. Leave quiet space (a clean margin) around the code. Crowding art or text into the quiet zone is a common print failure.
3. If you add a logo, keep it small and use higher error correction so scanners can recover covered modules.
4. Size for distance: a rule of thumb is roughly 1 inch of code width for every few feet of expected scan distance, then verify in the real environment.
5. Test on a phone after printing — screens and paper behave differently, and glossy finishes can glare under overhead lights.

Logos, colors, and brand polish

Branding is fine when it stays secondary to scannability. Use a free QR code generator with logo support, keep the center mark modest, and prefer high contrast over soft pastels. If your brand palette is low-contrast, reserve brand colors for the surrounding layout and keep the code itself near black-on-white.

Pairing a QR code with a short human-readable URL underneath helps when someone’s camera fails or they prefer typing. It also builds trust — people are more willing to scan when they can see where the link goes.

Why a code “stops working”

Static QR codes keep encoding the same string forever. If a link breaks, the destination site moved — not the QR image. Update the printed code when the URL changes, or point the code at a redirect you control on a domain you own so you can retarget without reprinting. Expired campaign pages, HTTP→HTTPS mismatches, and regional geo-blocks are frequent culprits after a successful launch.

Damaged prints matter too: folds through the finder patterns, ink bleed on cheap paper, and stickers placed too close to the quiet zone can all reduce read rates. When in doubt, regenerate a clean PNG from GenShelf’s QR tool and reprint rather than stretching a low-resolution screenshot. Dig deeper with how QR logos affect scan rates and print-ready QR codes.