Altarpiece unclear. Altarpieces can still broadly be divided into two types, the "reredos", which signifies a large and often complex wooden or stone altarpiece, and the "retable", an altarpiece with panels either painted or with reliefs. Retables are placed directly on the altar or on a surface behind it; a reredos typically rises from the floor. Retable-type altarpieces are often made up of two or more separate panels created using a technique known as panel painting. The panels can also display reliefs or sculpture in the round, either polychrome or un-painted. It is then called a diptych, triptych or polyptych for
Heller Altarpiece Heller Altarpiece The Heller Altarpiece was an oil on panel triptych by German Renaissance artists Albrecht Dürer and Matthias Grünewald, executed between 1507 and 1509. The artwork was named after Jakob Heller, who ordered it. Dürer painted the interior, Grünewald the exterior. In 1615, Dürer copyist Jobst Harrich painted a duplicate, which is now at the Städel of Frankfurt. The side panels, executed by Bosch's workshop basing from his drawings, are at the Staatliche Kunsthalle of Karlsruhe. The painting was commissioned by Frankfurt merchant Jakob Heller, for the Dominican church of the city. In 1615, the central panel, the only