Most people think that producing plastic parts is for big industry.
Modern materials have made it possible for anyone with a kitchen table to produce extremely high quality parts, out of a wide variety of plastics. This became possible with the advent of two different classes of materials. One is RTV Rubber, and the other is Polyurethane Casting Resin. Instead, it hardens up at room temperature. RTV rubbers typically come in a form that is the consistency of liquid honey.