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
Diptych of Philip de Croÿ with The Virgin and Child Diptych of Philip de Croÿ with The Virgin and Child The Diptych of Philip de Croÿ with The Virgin and Child consists of a pair of small oil-on-oak panels painted c. 1460 by the Netherlandish artist Rogier van der Weyden. While the authorship and dating of both works are not in doubt, it is believed but not proven that they were created as wings of a devotional diptych and that at some unknown time the panels were broken apart. A diptych panel fitting the description of the Mary wing was described in a 1629 inventory of paintings owned by Alexandre