Style of Neolithic pottery found in the northern part of the British Isles, especially the Hebrides, Western Isles, and Orkney, defined by Stuart Piggott in 1954 on the basis of an assemblage from the chambered tomb of Unstan on Orkney. Including both decorated and undecorated vessels, Unstan ware is diverse in the range of shapes and sizes represented. However, it can be typified by round-bottomed forms either as deep bowls and jars or as shallow bowls with a carinated profile produced by the application of a fillet or cordon of clay. The decoration is generally incised with oblique or horizontal lines, triangles, or a zone of hatched triangles. Dated examples of this ware fall within the period 3500-2800 BC, Unstan ware being slightly earlier than GROOVED WARE in the region.