3-D printing, and other additive manufacturing technologies, has built up a lot of buzz in the past few years. But the industry and the process itself may be older than you realize. As Proto Labs  CFO Jack Judd explained recently: "Most of the technology that is out there right now in the additive industry has been out there for 20 years. Currently the PR around the industry might make it look like an awful lot of what they do is brand new, but it's not."

Although 3-D printing companies garner the lion's share of attention today, Proto Labs is quietly becoming the dominant player in its own corner of the market. It offers more traditional injection-molded and machine-manufactured designs, serving customers who need a few parts quickly, not mass production. After seeing this success so far, I'm convinced the stock is ready to manufacture serious market-beating returns for investors.

1. Growing market opportunity
The "genius" of Proto Labs, as David Gardner put it when he first recommended the company in 2012, is that it reinvented a process, harnessing "the power of industrial manufacturing for clients whose modest needs would ordinarily get them laughed off the factory floor." For customers who only need a few -- or just one -- prototype made, 3-D printers simply aren't cost-effective. Proto Labs is there to fill the gap, with more material and more flexibility for these smaller customers.

Data from IBISWorld and Proto Labs

2. Better, faster, cheaper service

Time is of the essence in the prototype market, now more than ever before. Developers face a choice of either taking a project on themselves, possibly getting it wrong and having to go back to the drawing board with lost money and, maybe more importantly, lost time. Or they can go with Proto Labs -- which is dead set on making sure they get it right and get it fast.

Proto Labs' proprietary technology has helped the company streamline the entire customer experience, from ordering to production to shipping. The skilled labor conventionally required to quote and manufacture parts in low volumes puts competitors at an immediate disadvantage, which Proto Labs continues to exploit. Proto Labs customers conduct nearly all of their business with the company online.

With its low cost and quick turnaround time in a variety of materials and services, Proto Labs is garnering a stellar reputation as the first mover in its niche. That helps it win more business and will help it continue to gain share in this growing market.

Product developers face plenty of challenges, including slow turnaround time, difficulty sourcing low-volume parts, customer-unfriendly technology infrastructure, and high costs, Proto Labs sees these difficulties as pure opportunity. One great way is Proto Labs' Cool Ideas Award. It's the company's effort at accelerating innovation, helping entrepreneurs turn ideas into reality quickly and efficiently.

• The problem: Too many promising napkin sketches end up in the trash because product development resources and funding are scarce
• Proto Labs' solution: Bridge the gap between great idea and great product
• The winners: Here are three of 2013's winners; Proto Labs has the full story behind these and more Cool Ideas:

3. A wider moat
Proto Labs is growing, and its competitive position is strengthening, making it a compelling long-term investment. As more time passes, it becomes more difficult for competitors to take away Proto Labs' market. Its constant focus on customers, its growing advantage in technology, and its reputation in the industry all lead to a meaningful brand that is not only bringing new customers through the door but is also developing valuable repeat business. Judd summed it up nicely: "We have some really high barriers to entry. Again, the biggest barrier right at the front is proprietary software."

As a result, customers keep coming back to Proto Labs, as shown by the overwhelming share of revenue that comes from existing clients:

The Foolish bottom line
Proto Labs tends to get lumped in with 3-D printers these days, but that's OK; it certainly helps get the name out there. But dig a little deeper, and you'll see a market leader that continues to build out an already impressive competitive advantage in the manufacturing space where 3-D printers can't scratch the right itch. With its impressive market opportunity ahead and even more impressive (and growing) moat, the Proto Labs story is only beginning -- and it should reward any Foolish investor's portfolio for many years to come.