method). The following steps describe the indirect process, which can take two to seven days to complete. Produce a master pattern: An artist or mould-maker creates an original pattern from wax, clay, wood, plastic, or another material. In recent years the production of patterns using 3D printing of models produced by computer-aided design software has become popular using mainly resin based Stereolithography (SLA) or DLP 3D printers for high resolution patterns or standard PLA filament when high levels of accuracy are not required. If using a 3D Printed pattern proceed directly to step 5. Create a mould: A mould, known as the master die, is made to fit the master pattern. If the master pattern was made from steel, the master die can be cast directly from the pattern using metal with a lower melting point. Rubber moulds can also be cast directly from the master pattern. Alternatively, a master die can be machined independently—without creating a master pattern. Produce wax patterns: Although called wax patterns, pattern materials may also include plastic and frozen mercury. Wax patterns can be produced in one of two ways. In one process, the wax is poured into the mould and swished around until an even coating, usually about thick, covers the inner surface of the mould. This is repeated until the desired pattern thickness is reached. Another method involves filling the entire mould with molten wax and letting it cool as a solid object.If a core is required, there are two options: soluble wax or ceramic. Soluble wax cores are designed to melt out of the investment coating with the rest of the wax pattern; ceramic cores are removed after the product has hardened. Assemble wax patterns: Multiple wax patterns can be created and assembled into one large pattern to be cast in one batch pour. In this situation, patterns are attached to a wax sprue to create a pattern cluster, or tree. To attach patterns, a heating tool is used to slightly melt designated wax surfaces, which are then pressed against each other and left to cool and harden. As many as several hundred patterns can be assembled into a tree. Wax patterns can also be chased, which means parting lines or flashings are rubbed out using the heated metal tool. Finally, patterns are dressed (by removing imperfections) to look like finished pieces. Apply investment materials: The ceramic mould, known as the investment,