Is it a printing error? A pixilated maze? One of those puzzles where you have to cross your eyes to see the hidden image? Two-dimensional matrix bar codes are expanding into the mainstream. You can ...

Get unlimited access to ad-free articles and exclusive content. QR codes, those little black-and-white puzzle-like square matrixes that increasingly populate ads and promotional posters, are meant to ...

Among the many changes brought about by the pandemic is the widespread use of QR codes, graphical representations of digital data that can be printed and later scanned by a smartphone or other device.

QR codes, which had begun a fall into obscurity, have come roaring back. Many restaurants sport these matrix barcodes on tables as replacements for menus. One even appeared in an ad for cryptocurrency ...

The Covid-19 pandemic has drastically changed the way humans interact with each other and their surroundings. Physical health has become one of the top — if not the top — concerns of consumers ...