ranges roughly from 3.5 to 15 centimeters tall and wide, is put over the sprue base and the waxes. Most sprue bases have a circular rim which grips the standard-sized flask, holding it in place. Investment (refractory plaster) is mixed and poured into the flask, filling it. It hardens, then is burned out as outlined above. Casting is usually done straight from the kiln either by centrifugal casting or vacuum casting. The lost-wax process can be used with any material that can burn, melt, or evaporate to leave a mould cavity. Some automobile manufacturers use a lost-foam technique to make engine blocks. The model is made of polystyrene foam, which is placed into a casting flask, consisting of a cope and drag, which is then filled with casting sand. The foam supports the sand, allowing shapes that would be impossible if the process had to rely on the sand alone. The metal is poured in, vaporizing the foam with its heat. In dentistry, gold crowns, inlays and onlays are made by the lost-wax technique. Application of Lost Wax technique for the fabrication of cast inlay was first reported by Taggart. A typical gold alloy is about 60% gold and 28% silver with copper and other metals making up the rest. Careful attention to tooth preparation, impression taking and laboratory technique are required to make this type of restoration a success. Dental laboratories make other items this way as well. Textile use In this process, the wax and the textile are both replaced by the metal during the casting process, whereby the fabric reinforcement allows for a thinner model, and thus reduces the amount of metal expended in the mould. Evidence of this process is seen by the textile relief on the reverse side of objects and is sometimes referred to as "lost-wax, lost textile". This textile relief is visible on gold ornaments from burial mounds in southern Siberia of the ancient horse riding tribes, such as the distinctive group of openwork gold plaques housed in the Hermitage Museum, Saint Petersburg. The technique may have its origins in the Far East, as indicated by the few Han examples, and the bronze buckle and gold plaques found at the cemetery at Xigou. Such a technique may also have been used to manufacture some Viking Age oval brooches, indicated by numerous examples with fabric imprints such as those of Castletown (Scotland). Casting glass