How it's made. One plate with 50 wells sunk 1.6 mm, each with its label raised in a second colour, and three rings that drop into a well to mark the day, the date and the month. The ring is an annulus, so it frames the label rather than covering it - you can still read the date you are pointing at. No year anywhere: it is perpetual, and it never needs reprinting. Made flat in PLA, no supports.