Treasures of Ancient Glass

Mosaic Glass Vessels

Intro Glassmaking Techniques Glass Objects Virtual Gallery Core-Formed Rod-Formed Mosaic Glass Wheel-Made Free-Blown Mold-Blown Faceted Vessels

The complex and intricate technique of producing

vessels with mosaic patterning is attested as early as

the second half of the fifteenth century BCE in

Mesopotamia, was developed further in Egypt and

reached its floruit in Hellenistic and Roman

workshops. There are five basic steps in the

manufacture of mosaic glass vessels. First, rods of

different colored glass (figs. 1-2), are cold-bundled

together and heated until they fuse to form a mosaic-

like polychrome design that is visible on cross section

(figs. 3-5). 

Second, while still hot, this composite rod, commonly

termed a mosaic cane, is then pulled outward with a

pincers to make a long cane with a narrow diameter in

which the pattern is progressively miniaturized (fig.

6). Third, the mosaic cane is cut crosswise into

sections or lengths (fig. 7). Fourth, a flat disk or cake

of glass is assembled by placing the sections of mosaic

cane side by side and heated into order to fuse the

sections together (fig. 8). Last, the disk is placed over

a mold which upon slow re-heating in a kiln becomes

soft and then sags, or slumps into the mold. (figs.

9-10).

 

Images from:

D. F. Grose, The Toledo Museum of Art - Early Ancient Glass,

New York: Hudson Hilll Press, 1989,

p. 34 fig. 11

Vetri Antichi - arte e tecnica

Bologna, Museo Civico Archeologico,  1998 - 1999

p. 12