As described in "Type Classification Systems" in Chapter 2, while editing GW, a large-scale comprehensive union catalog of incunabula, German scholars compiled Typenrepertorium, a list of the different types used by printers during the incunabula period. They also started to publish a collection of the facsimiles of type specimens in 1907 through the organization called Gesellschaft für Typenkunde des 15. Jahrhunderts. The main figures involved in the compilation of this collection were distinguished incunabula scholars from various parts of Europe, including K. Haebler, I. Collijn (1875-1949), E. Voullième (1862-1930), V. Madsen (1873-1941) and K. Ohly (1892-1970). Entitled Veröffentlichungen der Gesellschaft für Typenkunde des 15. Jahrhunderts, the 33-volume collection of 2,460 plates containing facsimiles of incunabula types collected by these scholars was published over a period of more than 30 years. This useful material is commonly known by its abbreviation "GfT"; for example, the 158th plate is described as "GfT158."
The NDL owns GfT plates 1-2400 (Bd. 1-32) with the last volume missing. This section includes lists of GfT plates owned by the NDL in which facsimiles of type founts (a set of letters starting with A for which their corresponding punches were produced) have been created. The GfT plates include some 1,900 founts used by about 700 printers (of which 800 were used by German printers, 600 by Italian printers and 300 by French printers). You can see around 140 of these founts in this online exhibition.