passages of text. Zapf's work reached into a range of genres. Palatino is a warm, organic design inspired by Italian Renaissance calligraphy and printing. Melior suggests the work of the great German neoclassical printer Justus Erich Walbaum but also is based on the mathematical "super=elipse". 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. Dan Margulis commented on his death that that "you would have to say that his historical standing will be based on the first ten years of his professional career." Zapf's later releases for Linotype in the 1990s and 2000s, often created in collaboration with Akira Kobayashi, were radical reformations of his previous work, often removing compromises that had been necessary in the manufacture of metal type. In this period he created Palatino Sans, a more informal modulated sans serif than Optima. Zapf's typefaces have been widely copied, sometimes against his will. The best-known example may be Monotype's Book Antiqua, which was included in Microsoft Office and is often considered an imitation of Palatino. In 1993, Zapf resigned from ATypI (Association Typographique Internationale) over what he viewed as its hypocritical attitude toward unauthorized copying by prominent ATypI members. At a 1994 conference of the Raster Imaging and Digital Typography association in Darmstadt, Germany, a panel discussion on digital typefaces and designers' rights strongly criticized the alleged plagiarism of Zapf's Palatino, while several Microsoft attendees listened in the audience. In 1999, Microsoft worked with Zapf and Linotype to develop a new, authorized version of Palatino for Microsoft, called Palatino Linotype. Sometimes, however, Zapf worked with a font maker to make new versions of his existing typefaces created for another company. For example, in the 1980s Zapf worked with Bitstream to make versions of many of his prior typefaces, including Palatino, Optima and Melior, all with "Zapf" in their new names. Calligraphy Zapf is considered one of the great calligraphers, but he did not work extensively doing commercial lettering and calligraphy. His largest calligraphic project was the "Preamble to the United Nations Charter", written in four languages, commissioned by the Pierpont Morgan Library in New York in 1960, for which he received $1000. But his ideas about calligraphy indirectly influenced the look of the mid-20th century as he served as a consultant to Hallmark