Ovolo
Ovolo (or ovulo) in architecture, is a convex molding known also as the echinus, which in Classical architecture was invariably carved with the egg-and-dart ornament. The molding is called a quarter-round by woodworkers. This is not to be confounded with the "echinus" of the Doric capital, as this was of a more varied form and of much larger dimensions than the ovolo, which was only a subordinate molding.
This edge profile is commonly used as the inside profile edge of stile and rail interior doors and cabinetry doors.
See also
This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.