Moo card orders from About.me beware! Don’t get the black background or else the QR code won’t work. This is because the QR scanner can’t decipher the edge of the square appropriately. Proof? When the QR code is cut out and placed on a white BG it works just fine. Try it yourself on screen with this photo! One works, one doesn’t. Can you guess which one?

Might have to click on the image for the high-res version.