Zapf's work reached into a range of genres. While Palatino and Optima are warm, organic designs inspired by Italian Renaissance calligraphy, printing and stonecarving, he also designed a number of serif text fonts, such as Melior, in the more austere, classical style, following the work of the great German neoclassical printer Justus Erich Walbaum. His sans serif series URW Grotesk was designed for newspaper use and presents a wide range of widths and weights, reminiscent of geometric sans serif fonts like Futura but in a more eccentric style. Several of his more geometric designs, like both of these, make use of superellipses, squarish designs incorporating a slight curve. Opinion on Zapf's later designs has not always been favourable: Maxim Zhukov remembered his contemporary Adrian Frutiger commenting, with reference to URW Grotesk, that Zapf was "not a sans-serif man" at a conference in 1990, and graphic designer Dan Margulis commented on a retrospective that "he participated in the 1980s trend toward faces with very large x-heights and tight letterfits; his major works in that genre, Zapf Book and Zapf International, have deservedly been forgotten... you would have to say that his historical standing will be based on the first ten years of his professional career."