The bowl type typical of pottery known as Megarian bowl produced and appearing in the later 3rd century BC, unlike earlier wheel made wares with flat surfaces embellished only with paint, Megarian bowls were made in stamp decorated molds.
This method of manufacture gave them an embossed effect which have been intended to imitate metalwork. The bowl decorated on the outside with repeat rows creating a pattern to look like a pine cone, a register of egg and dart shape above, the bottom embossed with an eight petal rosette. The upper exterior painted in black.
On datring and origins of Hellenistic relief bowls, see Susan I. Rotroff, Hellenistic Pottery: Athenian and Imported Moldmade Bowls, Vol. XXII of the Athenian Agora (Princeton New Jersey: The AMerican School of Classical Studies, Athens 1982): 6-13. On Technique of manufacture, see Rotroff, Hellenistic Pottery: Athenian and Impoterd Moldmade Bowls 4-5. On the Hellenistic bowls in general, see J.J. Pollitt, Art in the Hellenistic Age, (Cambridge University Press 1986):256; John G. Pedley, Greek Art and Archeology, (Upper Saddle River, New Jersey: Prentice Hall 1993); Wlliam R. Biers, The Archeology of Greece: An Introduction (Ithaca: Cornell University Press 1980): 314-5; J.W. Hayes, Fine Wares in the Hellenistic World, in Looking at Greek Vases,Tom Rasmussen and Nigel Spivey eds. (Cambridge University Press 1991): 183-202.