It was already a trend, but now even more so: QR codes as a tattoo. They are graphic, hi-tech and eye catching - and the corona virus has accelerated the reputation of the design. QR codes are increasingly used to prove vaccination, immunity or a negative test result, for travel, access to restaurants, bars and clubs, or to be allowed access to sports venues. A temporary QR code tattoo, if used as a Covid Pass, is often seen as a bit of fun, or as a time saver: you don’t even have to get your smart phone out, you just show your tattoo to be scanned. A permanent QR code tattoo can be used to store other personal information, a poem line, your mother’s name or -cool- as a business card.

QR stands for ‘quick response’ and was invented in Japan nearly 30 years ago, used in the car industry for high-speed component scanning. A QR code is a two dimensional barcode that stores information, using standardised encoding modes: a machine-readable optical label. The code consists of black squares (data modules) arranged in a square grid on a white background. The design was influenced by the black and white pieces on a ‘Go’ board (Asian board game).

A QR code tattoo can be a temporary one – for instance with the design on medically approved decal paper. But if you go for the real deal, ink, there are some important tips. For the QR code to really work, it has to be very accurate. So, do think of the following:

• When a scanner reads a QR code, every dot is important. Go to a skilled tattooist who is very precise, knows how QR codes work, has experience in applying them, and knows how to build in ‘error correction’. This is needed for the code to remain scannable: skin and tattoo change with age, the ‘error correction’ enables the scanner to interpret the tattoo.
• Think carefully what you want to be included in the QR code tattoo. Choose permanent information (static content), rather than information that can expire. QR codes often contain a website address – but the website may not last and the QR Code tattoo will become useless.
• For a permanent tattoo, choose a simple text in a static QR code. Not something that may expire in the foreseeable future. A static QR code is permanent – but even this is debatable. Even a good QR code tattoo might stop functioning after a period of time, if they fade for instance.
• To create a QR code, you need a QR code generator. You can find these online. There are free ones, or you may have to pay for advanced options. Check out whether you can add design.

• Now for the actual tattoo. For the QR code tattoo to work, it needs to be slightly bigger than the one you see on your phone. The lines should not be too close together for the QR code to function.
• Place the QR code tattoo on flat body surface, such as the inner wrist above the veins, the back of the neck, the upper chest or the top of the thigh. Avoid curves.

Understandably, there are voices warning against QR code tattoos to prove your covid status. This type of tattoo, of course, should always remain a free choice.