Perhaps the most famous Hellenistic mosaic glass vessels are hemispherical bowls made of polychrome canes with spiral or star designs. The bowls were probably formed by fusing slices of the canes into a disk and slumping the disk over a mold. Most of these objects have rims that were fashioned by spirally twisting threads of different colors to produce a striped effect. Later, this technique was employed in Roman workshops. The earliest of the Hellenistic hemispherical bowls may have been made in the second half of the third century B.C., but most were produced a century later. The source of these colorful bowls is unknown. They have been found in many locations, including Greece, Italy, Egypt, and Syria. Mosaic glass bowls were a typical product of glass workshops in the eastern Mediterranean, and this example may well have been made there.