The current year has not been a kind one for investors in 3-D printing companies. In fact, shares of the two largest players in the field, 3D Systems (DDD 1.58%) and Stratasys (SSYS 0.10%), were down 50% and 30%, respectively, by the start of this week.

Does that mean you should go out and buy these stocks? Maybe, but it depends on how you're trying to build your portfolio. Motley Fool contributor Brian Stoffel, for instance, is busy building out a basket of 3-D printing stocks for his portfolio, but won't be buying shares of either of these industry leaders.  

He already owns shares of both 3D Systems and Stratasys, but watch the video below to see why he's looking elsewhere right now, and find out what 3-D printing company he just put his own money behind.