Static or dynamic URL QR code?
A static QR code stores your link inside the pattern itself. It never expires and works without any service in between, but the link can't be changed — if the page moves, you have to reprint.
A dynamic QR code stores a short QRCraft link that redirects to your page. You can change the destination at any time, pause the code, and see how many people scanned it, when and on which devices. Use dynamic codes for anything printed in quantity.
Tips for a QR code that scans every time
Keep strong contrast: a dark code on a light background scans most reliably. Leave a quiet margin around the code, and print it at least 2 × 2 cm (0.8 in) — larger if people will scan from a distance.
Shorter links produce simpler patterns that are easier to scan, which is another advantage of dynamic codes. Always test the printed proof with a couple of different phones before a big print run.