Calligraphy was the art of lettering, the creation of illustrations in the form of letters of an alphabet.
Hugh Culber joked with Jett Reno that partners that micromanage, in particular about wedding planning, had very specific expectations even around the calligraphic font used on materials. (DIS: "Through the Valley of Shadows")
Keiko Ishikawa once told a story of her grandmother, or "obachan"; when Keiko was 8, she used to help her obachan create beautiful pictures of Japanese calligraphy or Japanese brush writing and was responsible for bringing fresh water to clean the ink brushes. Keiko had forgotten the memory, but Tarmin from the Ullian delegation of telepaths helped her resurrect the forgotten memory. (TNG: "Violations")