Scratchbuilt models may also be made from brass and aluminum, cast in pewter (a low temp metal) and cast with 2-part resins in molds made of RTV rubber material. A scratchbuilding modeler should possess talents in the following areas: soldering, gluing, drilling, taping, grinding, sanding, cutting & shaping in metals and plastics, creating RTV molds (1,2 & 3 part types), painting & weathering, research of prototype material, casting in low temp metals, creating sketches and diagrams of what is being made, measuring in inches or millimeters, use of calipers and other specialized tools.