Floppy disk ceramic tiles

Found these ceramic tiles in the shape of floppy disks at the site of Australian design firm ENESS, who made a pretty cool game of augmented-reality Pong played on a whiteboard awhile back, and, I believe, are also responsible for making these. There’s nothing about how it was done, however, and the page is titled “5 1/4 inch,” in spite of the fact that these are clearly 3 1/2 inch floppies. Cool idea, though. Anyone have more info?