Lampworking is a type of glasswork where a torch or lamp is primarily used to melt the glass. Once in a molten state, the glass is formed by blowing and shaping with tools and hand movements. It is also known as flameworking or torchworking, as the modern practice no longer uses oil-fueled lamps. Although lack of a precise definition for lampworking makes it difficult to determine when this technique was first developed, the earliest verifiable lampworked glass is probably a collection of beads thought to date to the fifth century BC. Lampworking became widely practiced in Murano, Italy in the 14th century. In the mid 19th century lampwork technique was extended to the production of paperweights, primarily in France, where it became a popular art form, still collected today. Lampworking differs from glassblowing in that glassblowing uses a furnace as the primary heat source, although torches are also used.
Early lampworking was done in the flame of an oil lamp, with the artist blowing air into the flame through a pipe. Most artists today use torches that burn either propane or natural gas, or in some countries butane, for the fuel gas, mixed with either air or pure oxygen as the oxidizer. Many hobbyists use MAPP gas in portable canisters for fuel and some use oxygen concentrators as a source of continuous oxygen.
Lampworking is used to create artwork, including beads, figurines, marbles, small vessels, Christmas tree ornaments, and much more. It is also used to create scientific instruments as well as glass models of animal and botanical subjects.
Lampworking can be done with many types of glass, but the most common are soda-lime glass and lead glass, both called "soft glass," and borosilicate glass, often called "hard glass." Leaded glass tubing was commonly used in the manufacture of neon signs, and many USA lampworkers used it in making blown work. Some colored glass tubing that was also used in the neon industry was used to make small colored blown work, and colored glass rod, of compatible lead and soda-lime glasses, was used to ornament both clear and colored tubing. The use of soft glass tubing has been fading due, somewhat, to environmental concerns and health risks, but mainly due to the adoption of borosilicate glass by most lampworkers, especially since colored glasses compatible with clear borosilicate were developed.