the stress in the piece will cause a failure. Lampworking Similar to glassblowing, Lampworking (also called flameworking or torchworking) is a style in which the artist manipulates glass with the use of a torch – rather than a blowpipe or blow tube – on a smaller scale. Once in a molten state, the glass is formed by blowing and shaping with tools and hand movements. Though typical lampworking art takes the form of beads, figurines, marbles, small vessels, Christmas tree ornaments, and other such things, it is also used to create scientific instruments as well as glass models of animals and botanical subjects. Kiln-formed glass Kiln formed glass is usually referred to as warm glass, and can be either made up from a single piece of glass that is slumped into or over a mould or different colours and sheets of glass fused together. The process of hot glass is highly scientific in that the types of glass and temperatures that they must be fired at is quite complicated operation to undertake correctly. Art glass that is kiln formed usually take the form of dishes, plates or tiles. Glass that is fused in a kiln must be of the same co-efficient of expansion (CoE). If glass that does not have the same CoE is used for fusing, the differing rates of contraction will cause minute stress fractures to form and, over time, these fractures will cause a piece to crack. The use of polarizing filters to inspect the work will determine if stress fractures are present. Cold glass Cold glass is worked by any method that does not use heat. Processes include sandblasting, cutting, sawing, chiseling, bonding and gluing. Sandblasting Glass can be decorated by sandblasting the surface of a piece in order to remove a layer of glass, thereby making a design stand out. Items that are sandblasted are usually thick slabs of glass into which a design has been carved by means of high pressure sandblasting. This technique provides a three-dimensional effect but is not suitable for toughened glass as the process could shatter it. Copperfoil technique The technique of using copperfoil is mainly used in the construction of smaller pieces such as Tiffany style lamps, and it was, in fact, frequently used by Louis Comfort Tiffany. It consists of wrapping cut sections of glass in a self-adhesive tape that is made out of thin copper foil. This