2013-03-22

How do I use QR Codes?

QR Codes work fine on almost any surface. The important thing for the QR Code app is that the contrast is high, that the QR Code is not damaged or obstructed, and that the camera is held away far enough for it to focus.

Rotation angle doesn’t matter. Neither does size and angle, within reason. There’s also need for sufficient light, so that the camera sees the code clearly.

Recommended size is ~2 cm/~1″ square in normal magazine print. Also, make the ratio between size and expected reading distance approx. 1/10.

If the QR Code will be read from a longer distance, a ratio of 1/5 (size/distance) is fair.

Optimally the QR Code is black-n-white, but provided the background is light and the QR Code modules are dark also colored QR Codes work. A good advice is to check the contrast value in CliqTags to see that the contrast is above 50%. Don’t use a dark background and a light QR Code, as some readers have a problem with that.

CliqTags generates QR Codes in pixel (PNG, GIF, JPEG) and vector (EPS, PDF, SVG) formats. We recommend EPS or PDF for print, and PNG for other uses. Never use QR Codes in JPEG format in print.

Increase the error correction level if you overlay a logo or will print on flexible or rough material, and of course test before going to print in the size it will be printed in.

For users that can’t use or don’t understand QR Codes you can complement with an SMS request under the QR Code, a la Text cl [ID] to 72672 (currently this only works in Sweden), where [ID] is the site’s identity (the same as in the link to the site: cqt.se/[ID]), or you may add an NFC tag, provided it’s feasible (best suited for large posters) and that you are aware that iPhone doesn’t support NFC. For more information about this, see

It’s very important to explain the purpose and benefit of reading a QR Code, in close proximity to the code. Otherwise many will simply skip doing so.