Treasures of Ancient Glass

Rod-Formed Vessels

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

Closely related to core-forming, the technique of rod-

forming allows the glassmaker to fashion long

cylindrical vessels, beads, amulets, and ornaments

such as the ear plugs by winding successively re-

heated glass canes around a metal pike. This pike or

copper-containing metal rod was in the earliest

periods covered with a parting layer of calcite, clay,

and sand in varying proportions which served to

separate the resulting glass object from the rod easily.

While the metal rod was rotated, it was covered by a

glass trail in order to form the object. Winding

became the most popular method for the

manufacturing of glass beads. Many beads still exhibit

traces of the parting layer which adheres to the inner

side of the bead’s rod hole. Some examples even

reveal the glass thread´s tail end which was not united

with the body of the bead. Pendants and other small

articles can also be formed on the on the tips of such

rods if coated with a separating agent. The diameter

and exact shape of the rods vary, depending on the

required size of the interior cavity of the vessel or

object. The rod is removed before annealing.

 

Images from:

Vetri Antichi - arte e tecnica

Bologna, Museo Civico Archeologico, 

27 ottobre 1998 - 27 giugno 1999,

p. 6