The objects produced in the hot-worked technique range widely in place of origin, from Egypt to Central Asia, and in time, from the early Islamic period in the seventh century to the thirteenth. They represent a type of glass that is manipulated and decorated while the blown vessel is still hot and malleable and are subdivided into three categories according to the specific decorative technique.
Vessels with Applied Decorative Trails
Hot trails of glass, which have roughly the consistency of molasses, were “poured” over the vessel while the inflated object, which was still attached to the pontil, was rotated slowly to form a spiral pattern along its body. Often, the trails were manipulated with a pointed tool or a fine pincer to create patterns. Such objects were produced mostly in Syria and Egypt from the tenth to the fourteenth century. In the group of animal-shaped cage flasks, which belongs to this category of hot-worked glass, the trails form an openwork cage.
Works with Impressed Patterns
These objects were decorated using metal tongs with circular or square ends that had a carved design on one or both sides. The tongs were applied against the vessel and the pattern was impressed in relief on the exterior wall. Most objects of this type are small bowls decorated with a limited range of geometric, pseudo-vegetal, and zoomorphic motifs and attributed to Egyptian workshops operating in the ninth and tenth centuries. Tong-impressed vessels are usually bowls, beakers, and pitchers—objects that have an open shape—but there are also bottles formed by two separate sections that were stamped before they were joined. Small roundels and larger medallions embossed with a die also belong to this group; the former are usually attached to the walls of globular bottles; the latter were used in eleventh- and twelfth-century Afghanistan to decorate window grilles.
Glass with Marvered Trails
In this technique the trails were integrated into the blown vessel using a rotating motion against a marver (a polished stone or an iron slab; hence the term “marvered”), so that they became flush with the surface. The trails were tooled and “combed” with a toothed implement into wavy, arched, or festooned patterns. The trails are almost always white, providing a pleasant contrast with the usually dark-colored vessel. Glass with marvered trails was produced continuously in Syria and Egypt from the early Islamic period to the fourteenth century.
Carboni, Stefano, and Qamar Adamjee. “Hot-worked Glass from Islamic Lands.” In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art, 2000–. http://www.metmuseum.org/toah/hd/hotw/hd_hotw.htm (October 2002)
Allan, James, ed. Islamic Art in the Ashmolean Museum. 2 vols. Oxford: Oxford University Press: 1995. For marvered glass, see pp. 1–30, 31–50.
Carboni, Stefano. Glass from Islamic Lands: The al-Sabah Collection, pp. 163–95, 261–89, 291–321. New York: Thames & Hudson, 2001.