Winged altarpiece

The technical terms are derived from Ancient Greek: τρίς: trís or "triple"; πέντε: pénte or "five"; πολύς: polýs or "many"; and πτυχή: ptychē or "fold, layer".

[1] There are often images on both the insides and outsides of the wings, enabling the altarpiece to display completely different views when open and closed.

It was usually the custom to keep the wings closed except on Sundays or feast days, although very often the sacristan would open them for tourists at any time for a modest tip.

Small winged paintings, usually triptychs, were also owned by the wealthy for private devotions, and services in the house; they had the advantage that the open view was fairly well protected when covered up during travel.

It was never as popular in Italy, where there were many polyptychs, but usually built without hinges, so always "open", even if there were also images on the back, as in the Maestà by Duccio for Siena Cathedral.