In the 1960s, the hallmark of Czechoslovak New Wave's films were improvised dialogues, black and absurd humor and the occupation of non-actors. Directors are trying to preserve natural atmosphere without refinement and artificial arrangement of scenes. A personality of the 1960s and the beginning of the 1970s with original manuscript and psychological impact is František Vláčil. Another international author is Jan Švankmajer, a filmmaker and artist whose work spans several media. He is a self-labeled surrealist known for animations and features.