The orginal mother of invention for 3-D printing was Hull's necessity for quicker prototyping. Today, the speed and convenience of rapid prototyping allows firms, small and large, to be more nimble and to produce different versions of a product overnight, test them, and produce inproved version without delay. This not only improves the production process, but also has a profound impact on how creative inventors can be in their product development. A rejected part or a dud no longer costs a lot of money or time, but can become a creative part of experimentation and research and development. However there are lots of other advantages for firms.