What is Resin

Thank you very much for that explanation!

Resin is used to refer to a 2-part compound used to make model parts and kits. Properly only one of the ingredients is resin with the other being hardener. Most resins used for models are polyurethane. The process for use is similar to epoxy glues or two part auto body filler aka Bondo. The advantage compared to injection-molded plastic is that it does not require a half-million dollar machine to make a part, just a relatively inexpensive mold into which the mix is poured. This makes it very useful for cottage industry producers. Disadvantages of resin include toxicity of the dust when sanding, brittleness, weight, and a lack of strength in parts like struts or tank gun barrels, and a tendency to warp in some cases.