Boxed lunches are the norm for Korean school children and workers which is probably why Lock&Lock headquartered in Seoul seems to be dominating the world wide market for airtight containers. Their YouTube channel has recently been updated with a video showing the construction of a QR Code made from candy, which regular readers will have seen before. For example this QR Code made from Frisk mints and this one made from M&M’s. What makes this particular construction unique is that it uses a subtraction method (video below). Every module (matrix square) is given a chocolate and then one by one they are removed from the appropriate squares to reveal the white space below. The operation is performed by the dexterous use of chopsticks! The QR Code resolves to a Lock&Lock mobile page but there is some IP address checking and outside of Korea you just get to see a non-mobile page in English.