A QR code can bridge a poster, package, or sign to a digital destination. Use a stable HTTPS link you control when possible, and print a short human-readable address or instruction beside the code. That gives people a fallback and tells them what they are about to open.
Leave the blank quiet margin intact, use strong contrast, and test the final printed material at the expected viewing distance. Curved packaging, glare, and small size can defeat a code that scanned perfectly on a monitor. Avoid opaque shorteners that might expire or conceal the destination. Treat unfamiliar QR codes as unfamiliar links: inspect the destination before signing in or downloading anything.
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