Hitler considered all himself to be a pretty knowledgeable man in the areas of art. He opposed all forms of art he deemed “un-German” which included artworks by artists such as Picasso. The only form of art he would allow is the classical realistic form in which the art works glorifies and represent all that is good in Germany. He formed a tribunal group consisting of 4 men who toured the country to eradicate any arts the Hitler considered "degenerate or decadent arts." Hitler would hang up arts to display what was acceptable and what was not. He also despise any new forms of arts because he believed that they all stemmed from the USSR. Thar's why many artists left the country because of the strict rules Hitler imposed what they were and weren't allowed to do, which gave them no space for creativity in their work.
While he was the chancellor of Germany, Hitler created the Chamber of Cultures, which was split into 7 sections: fine arts, music, theatre, literature, press, radio and film. There were rules which was backed by the law. Every artist that wanted t work in Germany had to get approval from the Chamber first and join the chamber of Visual Arts. The artists could be expelled as well, and once they were, their career is over because they're now on the blacklist. Gestapos would pay surprised visits to artists to make sure they were following the rules. Hitler introduced painting competitions in order to encourage the people to paint in the "acceptable" form, in which the winner receives financial rewards.