[2] After the war, Peiner studied at the Düsseldorf Art Academy, since 1919, after initially taking private lessons from Wilhelm Döringer, a friend of his father.

In 1923 Peiner married Marie Therese "Resi" Lauffs and moved to Bonn to live with his in-laws.

During this time, through the mediation of his friends, the architect Emil Fahrenkamp and the entrepreneur Walter Kruspig (since 1930 general director of Rhenania-Ossag), Peiner accepted artistic commissions for the design of church, insurance and industrial buildings.

In 1931, Peiner settled in Kronenburg and began converting several houses in the historic town center into a studio.

Peiner style was closer to the New Objectivity during the Weimar Republic, but he would accept the Third Reich, and would become one of its official artists.

Peiner owed his appointment not only to his acquaintance with the provisional director of the art academy, Julius Paul Junghanns [de], but probably also to his painting Deutsche Erde, or German Land, with which he supported the emerging Nazi ideology of blood and soil.

The painting was donated by the town of Mechernich to Schleiden district administrator Josef Schramm.

Schleiden NSDAP district leader Franz Binz handed it personally to Adolf Hitler.

With the consent of Hermann Göring, Peiner undertook a study trip to East Africa from February 1935, which Kruspig had organized and financed.

On March 23, 1936, the minister for art, science and popular education issued a decree establishing the “Landakademie Kronenburg der Staatliche Kunstakademie Düsseldorf”.

His Nazi commissioned works included the cycle of the German Battles of Fate for the Marble Gallery, also known as the Long Hall, of the New Reich Chancellery, in Berlin, the drafts of which are now exhibited in the Rheinisches Landesmuseum Bonn.