GlassBlowing

Glassblowing is a glassforming technique in which molten glass is inflated into a bubble through a hollow steel rod or blowpipe, allowing the creation of hollow vessels and sculptural forms. The practice emerged in the late 1st millennium BCE in the eastern Mediterranean and spread through the Roman world. By the medieval period it had become widespread in Europe, with major centers such as Venice playing a key role in development and refinement.

The basic process involves gathering molten glass on the end of a blowpipe, rolling it to shape the molten mass, and blowing air into the pipe to form a bubble. The piece is continually reheated to keep it workable. Shaping is done with tools such as jacks, tweezers, and shears, and may involve rolling on a marver or inflating through molds to achieve specific forms. After blowing, the piece is annealed in a kiln or annealing lehr to relieve thermal stress and prevent cracking. Techniques vary from free-blown work to mold-blown forms, and related methods include lampworking for small items using a focused flame.

Materials are typically soda-lime glass, with color achieved by metal oxides. Finishes range from clear, transparent vessels to richly colored sculptures. Notable centers include Murano in Italy and Bohemia, which influenced glass styles and trade. Glassblowing is practiced in studios, hotshops, and factories, producing art glass, functional vessels, and scientific glassware where precision is essential. Safety considerations include high temperatures, chemical fumes, and protective equipment.