In his State of the Union address earlier this year, President Obama argued that 3-D printing could "revolutionize the way we make almost everything." His speech echoed a sentiment that has been gaining traction among entrepreneurs and techies for some time now.

Three-dimensional printing, also known as additive manufacturing, has been around since the late 1980s and has produced some exciting advances. Companies in the industry have printed aerospace parts, industrial manufacturing equipment, and even human stem cells. One company is working on a technique to print functioning human organs. Although all of this is promising, 3-D printing technology still has a long way to go.

The industry is poised to grow to $3 billion globally by 2018, up 56 percent from 2012, according to a study by the market research firm Global Industry Analysts. So far, big companies have dominated the sector.

"If you're talking about using 3-D printing for actual finished products, it's really aerospace and the medical industry driving most of this growth," says Terry Wohlers, president of Wohlers Associates, a firm that provides consulting services to the 3-D printing industry.

The average 3-D-printed product costs roughly $4 a cubic inch to produce, according to Wohlers. Generally, it's cost effective to print only items that can be produced in low volumes with high markups--such as airplane parts or hip replacements. When it comes to more commoditized items, such as children's toys or the casings for TV remotes, mass-scale injection molding in China is still significantly cheaper.

At this stage, prototyping seems to be the most effective 3-D printing application. Stratasys is an Eden Prairie, Minnesota-based manufacturer of high-end 3-D printers that allow companies like BMW to innovate on the fly. For example, BMW uses Stratasys printers to create new thermoplastic tools for its assembly-line workers. The tools are more lightweight and ergonomic than traditionally made tools.

"Being able to print new components for their factories as fast as they can innovate is already making manufacturing firms incredibly agile," says Bruce Bradshaw, Stratasys's director of marketing. "As a result, companies will be less tempted to outsource manufacturing to places that lack the expertise to use this type of technology."

Matthew Tran is the co-founder of Boosted Boards, an electric-skateboard manufacturer based in Sunnyvale, California. He is fortunate enough to share office space with a robotics company, which has given Boosted unfettered access to a number of 3-D printers. The company used 3-D printers to generate a plastic enclosure for an early prototype of the skateboard's hand-held remote controller. "You get the part within hours, depending on what size it is," says Tran. "If you had to machine that part, it could take a couple of days."

To some degree, even businesses that don't have access to industrial 3-D printers can still take advantage of the technology. Start-ups such as MakerBot and Formlabs have introduced a number of consumer-level 3-D printers that cost less than $3,000. The consumer models don't offer the same precision and features that industrial printers do, but entrepreneurs can still use them to create parts and components of finished products.

Wohlers offers a tempered vision of 3-D printing. "It won't be bringing back manufacturing to the U.S. in the traditional sense," he says. "But it's going to lead to a whole host of new business models and a different way of thinking when it comes to start-ups."

That trend has already started. Last December, Staples announced a partnership with 3-D printer manufacturer Mcor Technologies to provide 3-D printing services in Staples stores. Down the road, small companies could sell digital files for their products online. Customers would print their purchases at the local 3-D print shop and have them delivered to their homes that same day.

So will 3-D printers produce just about everything one day? That's a long shot, says Bradshaw of Stratasys. "There's a lot of talk that eventually your mom is going to have a 3-D printer in her living room," he says. "I just can't see that happening."