Most ancient Egyptian beads were made of faience, a glass-composite glaze which was introduced as early as the Pre-Dynastic period. According to Egyptologists, most beads were made on an axis, probably of thread, which would burn up during firing, leaving a hole. Disc, ring and tubular beads were made by coating the axis with the unfired body-paste, rolling the cylinder to an even diameter on a flat surface, and then scoring it with a knife into sections of the desired length. Other shapes, such as ball beads, were rolled between the hands and perforated while still wet with a stiff point such as a wire needle. The beads were then dried, coating with glaze (if the glaze had not already been mixed with the paste), and fired. The firing process often gave the beads a beautiful translucent quality. The majority of faience beads are blue or green in color, but black, red yellow and white ones were also produced, especially in the New Egyptian Kingdom.