Etruscan goldsmiths were highly skilled, particularly in their delicate use of granulation (powder-like gold grain) and filigree (fine wires). Motifs such as acorns, lotus, palmettes, spinxes, rosettes were foreign imports. Eastern trade played a decisive role in the economic power of the Etruscans and in their art. In the later period (550-400), Etruscan jewellery is often indistinguishable from Hellenistic Greek works. Through trade they acquired gold, techniques and oriental design motifs. But there were also local types such as the densely decorated bag-shaped (baule) earrings. They are in the shape of a cylinder and surmounted by a semi-circular ornamental plate.