There are as many ways of scratch-building models as there are modelers, but generally the modeler obtains plans of a prototype, or designs their own, transfers these plans to paper or other material as patterns (much easier since the arrival of household computer printers and copiers), and uses these patterns to cut, trim and affix the stock together to form the model. Finishing work (such as sanding and polishing, painting, weathering, distressing by forming dents and rust, dust, etc.) is done to complete the model and (hopefully) bring it to a lifelike state.