The MAK – Austrian Museum of Applied Arts is in possession of the original of the famous manuscript of Practical Art in Metals and Hard Materials by Gottfried Semper (1803–1979). 1867, this study which is now published in book form was donated to the museum by Semper, and since then has been kept in the MAK Library and Works on Paper Collection. In Practical Art in Metals and Hard Materials Semper expounds his phenomenology of architectural materials juxtaposed with his theoretical positions. The study discusses the systematisation of the ideal museum and includes valuable ideas and suggestions. Moreover, it surveys institutions, objects, and artists that were considered as having model character by Semper and assumably also had an influence on his own work. The commented edition of Practical Art in Metals and Hard Materials includes a transcription of the original manuscript with a critical apparatus as well as introductory texts by experts of Semper’s work. It is intended to make a substantial contribution to the research of the founding period of modern Architecture, design, and modern museology. The book was awarded the Austrian National Award for the most beautiful art book of the year 2007.