1911 Encyclopædia Britannica/Triptych

TRIPTYCH (Gr. τρίπτυχος, three-fold, made in three layers, τρι-, τρεῖς, three; πτυχή, a fold, πτύσσειν, to fold, double over), a painting, carving or other decorative design, executed on three compartments or panels, so constructed that the two wings may fold on hinges over the centre-piece; the backs of the wing-pieces are often-also painted, carved or otherwise decorated. The subject of the side-pieces are usually appropriate and subsidiary to that of the centre. The triptych is most frequently designed as an altar-piece. An earlier use of the term is for a set of three woode11 or ivory writing tablets, hinged or otherwise fastened together, the central tablet being waxed on both sides for the impression of the stilus or writing implement, the outer tablets only on the inside. The three tablets thus formed a small book.