[Ben Bartlett] recently got engaged, and the proposal had a unique bit of help in the form of a 3D-printed hexagonal mirror array, whose mirrors are angled just right to spell out a message with th… ...

This is the actual 3D printable hexagonal mirror array created by Mr. Bartlett. There are three materials: 1 inch (about 2.54 cm) hexagonal mirror tile, PLA filament used in 3D printers, and adhesive.