Its characteristic rough surface and rich variety of colours, from brown via red to purple, also contributed to the material's popularity.
The angular bricks were combined in various arrangements, creating a rich ornamental repertoire, including specific forms of sculpture.
Ernst Barlach also created clinker statues, such as the frieze Gemeinschaft der Heiligen ("community of saints") on St. Catherine's in Lübeck (completed by Gerhard Marcks).
Examples were created all over the Ruhr, including industrial architecture (assembly halls, office buildings, water towers, etc.)
An important example is Alfred Fischer's Hans-Sachs-Haus in Gelsenkirchen, planned as multi-functional a building but eventually used as the city hall.
Also in Gelsenkirchen, in the Ückendorf area, is the main work of Josef Franke, the Parabola Church of Heilig-Kreuz (Holy Cross).
Other important Brick Expressionist buildings in the Ruhr area are the police headquarters, Bert-Brecht-Haus and city hall in Oberhausen, Alfred Fischer's offices for the Regionalverband Ruhrgebiet (regional development authority) in Essen, the BOGESTRA building and the police headquarters in Bochum, and the pediatric surgery ward of Dortmund city hospital.
Other prominent examples of Brick Expressionism include the Grossmarkthalle in Frankfurt am Main, the Technical Administration Building of Hoechst AG in Frankfurt-Höchst, and Grundtvig's Church in Copenhagen