Naive art first became popular at the end of the 19th century. Until that time, this form of expression, created by untrained artists and characterised by spontaneity and simplicity, enjoyed little recognition from professional artists and art critics. Influenced by primitive arts, naive painting is distinguished by the fluidity of its lines, vivacity, and joyful colours, as well as by its rather clean-cut, simple shapes. Naive art counts among it artists: Henri Rousseau, Sraphine de Senlis, Andr Bauchant, and Camille Bombois. This movement has also found adherents abroad, including such prominent artists as Joan Mir, Guido Vedovato, Niko Pirosmani, and Ivan Generalic.