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
Ildefonso Altarpiece was commissioned for the Brotherhood by his widow shortly after his death. Ildefonso Altarpiece The Ildefonso Altarpiece is a triptych painting by Peter Paul Rubens, dating to between 1630 and 1631. It is now in the Kunsthistorisches Museum of Vienna. It is named after the central panel, which shows Saint Ildefonsus's vision of the Virgin Mary, in which she gave him a "casula". On the side panels are Isabella Clara Eugenia and Albert VII, regents of the Spanish Netherlands, with their patron saints Albert and Elisabeth of Hungary. Albert had founded the Ildefonso Brotherhood in the church of Saint Jacques-sur-Coudenberg