Along with the owner's daughter, sister Teréz and Julia Zsolnay, he was the most important artist of that factory during its fast development and worldwide success at the end of the 19th century.
[3] He studied sculpture at the University of Applied Arts in Vienna and at the suggestion of his professors he went to Pécs.
[5] Klein, however, brought breath of European art of that time, and especially in the German cultural circle of then-popular style of historicism, specifically: Neo-Renaissance.
[7] Although he was much less productive in sculpture, it is certainly worth mentioning his depictions of famous scientists (Leonardo da Vinci, Newton, Watt...) for the Polytechnic in Budapest.
In accordance with the artistic currents of his time, he united the ideas and styles of large centers with local features,[9] and despite his early death at the age of 28, he left an indelible mark on the Austro-Hungarian ceramic art of his time.