The recession cooled off the hot sales growth for rapid prototype machines, but the industry -- dubbed "additive manufacturing" -- continues to get a boost from very low-cost three-dimensional printers.

Because of demand for open-source 3D printers, unit sales of additive manufacturing equipment grew by 13.9 percent worldwide, the report said.

Instead of rapid prototyping, Wohlers Associates now uses the term additive manufacturing. That is a process of joining materials to objects from 3D model data, usually layer-by-layer (as opposed to subtractive manufacturing such as machining).

The 250-page report includes new sections on open-source 3D printers and the state of business among service providers.

The research firm also predicts continued growth for the direct production of finished goods using additive manufacturing. So far, two markets have emerged. A market of professionals includes products for medical, dental, aerospace, automotive and motor sports industries. Consumers account for the second market, including furniture and home accessories, toys, game avatars and fashion products.

The technology allows you do make products in quantities from one to several thousand.