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".