The Esterbrook 556 School Medium Firm vintage dip pen nib is a stiff pen with higher shading properties, and is capable of producing finer hairlines. The 556 is the archetypal "school pen", a resilient, firm pen point that can still achieve good shading, and is good for Spencerian, letter writing, and offhand sketching. Bob Hurford describes the Esterbrook 556 as "a great nib that never seems to wear out".