While injection-molding is the predominant manufacturing process for plastic models, the high costs of equipment and making molds make it unsuitable for lower-yield production. Thus, models of minor and obscure subjects are often manufactured using alternative processes. Vacuum forming is popular for aircraft models, though assembly is more difficult than for injection-molded kits. Early manufacturers of vacuum formed model kits included Airmodel (the former DDR), Contrail, Airframe (Canada), Formaplane, and Rareplanes (UK). Resin-casting, popular with smaller manufacturers, particularly aftermarket firms (but also producers of full kits), yields a greater degree of detail moulded in situ, but as the moulds used don't last as long, the price of such kits is considerably higher. In recent times, the latest releases from major manufacturers offer unprecedented detail that is a match for the finest resin kits, often including high-quality mixed-media (photo-etched brass, turned aluminum) parts.