In a perfect world, every mold would be built and the first shots would be ready for production. Yet as anyone who has designed products, built tooling or purchased molded parts knows it is never that simple. Changes are going to occur during at some point and modifications will be required.

The STL file format has become recognized as the standard for RP machines. Note that STL files are produced by CAD systems that are based on surface and/or solid modeling only. 2-Dimensional and Wireframe CAD systems do not output STL files.