Because lead oxide-containing glass (commonly known as artificial crystal) has a diamond-like high refractive index and high fluidity at high temperatures, casting glass is often made of artificial crystal. In the Chinese market, the above-mentioned dewaxed cast lead crystal glass products are generally referred to as colored glass. The dewax casting method can be used to produce complex and exquisite crafts.
The dewaxing casting glass process was developed from the ancient casting process. In the late Neolithic period more than 5,000 years ago, ancient Chinese artisans used the lost wax casting process in the manufacture of bronzes. At that time, according to the plasticity and thermal volatility of beeswax, the craftsmen first carved the beeswax into a wax mold of the desired shape, and then wrapped the clay outside the wax mold and reserved a small hole, dried and calcined to vaporize the wax mold. At the same time, the clay becomes a ceramic shell, and the inner wall of the shell leaves a negative mold of the wax mold. At this time, the molten metal is injected into the casing along the small hole, and after cooling, the casing is broken to obtain the desired metal slab. The basic principles of modern lost wax casting technology are the same, but more complicated and precise. This is mainly reflected in the stricter requirements for the accuracy of the shape of the wax mold. In the modern process, the wax mold is obtained not only by direct engraving of the wax, but also by molding the metal mold (plate) with a silicone mold to obtain a female mold, and then waxing the silicone mold to obtain a wax mold. The casting material is no longer clay, but instead casts gypsum. Such products are much more elaborate than ancient castings.