Estiennium is a humanist sans serif with a quirky personality. The design began with the uppercase O, which was originally drawn as a modified super ellipse with its corners clipped off. The bowls of the uppercase and lowercase letters follow the same shape but stand off from the geometrically flared stems as if they had been slowly pulled away to show the connective tissue that binds them together.

Estiennium is named for the first family of French printers, the Estiennes. This was intended primarily as a text face with a series of weights — regular, demibold, bold, extrabold and black — that would allow greater variation than the usual weights of most families.