Timner has a long history of personal and collective exhibitions in German and Italian art galleries and institutions. His works have been acquired in both public and private collections, such as the Stadtmuseum in Berlin, the Berlinische Gallery in Berlin, the Deutschen Historischen Museum in Berlin, the Kommunale Galerie Charlottenburg-Wilmersdorf in Berlin, the House of the Church, the Evangelical Church in Berlin and Brandenburg, the Hamburger Arbeitsmuseum, the Staatliche Museen in Dresden – Neue Galerie, the IGMetall in Frankfurt am Main, the San Francesco Museum complex in Trevi (Italy), the Palazzo dei Diamanti in Ferrara, the Preussische Schlöesser Foundation and Gärten Berlin Brandenburg.
