Scanning QR Codes on Curved, Wrinkled or Shiny Surfaces

Real-world codes are not always flat. Bottles, bags and tins can bend the pattern out of shape.

What goes wrong

• Curves stretch or squeeze the modules near the edge.
• Wrinkles create shadows and break the pattern.
• Shiny foil reflects light into the camera.
• Transparent wrap adds glare and a second reflection.

What helps

Curved surfaces

• Face the code directly, so the centre is square to the camera.
• Step back a little to reduce the effect of the curve.
• Rotate the item so the code sits at the flattest part.

Wrinkled paper or bags

• Smooth the surface with your hand.
• Flatten the item against a table if possible.
• Light the code evenly to reduce shadow.

Shiny materials

• Tilt to move reflections away.
• Block direct light with your body or hand.
• Try a different position relative to the window or lamp.

Why some codes are more robust

A code with a higher error-correction level can survive some distortion. A larger code also copes better, because each module covers more of the camera's pixels.

If you are designing packaging

• Put the code on the flattest part of the pack.
• Use a matt finish over the code area.
• Keep the code away from seams and folds.
• Choose high error correction.
• Test on the real, filled pack.

Tips

1. Flatten, face, light.
2. Move around the glare.
3. Test real samples when designing.

QR Code Scanner opens straight to the camera, so you can start moving around a tricky code right away.