How it's made. The formula is set from real mathematical type (superscripts, fractions, radicals and Greek all typeset properly), then grown 3 mm into a silhouette plate that joins every symbol into one piece. Standing: symbols 12 mm deep on a 3 mm plate, a 25 mm foot bar the plate runs into, the class line raised on the foot's front. Wall: symbols 8 mm deep, two keyholes on the back. Symbols and plate in their own colours. PLA, no supports, printed flat on its back.