The U.S. Patent and Trademark Office in Alexandria, Va., recently hosted a fascinating display of technology. 3D Systems (NYSE:DDD), Stratasys (NASDAQ:SSYS), and other top companies involved in additive manufacturing, or 3-D printing, displayed their wares in the same room.

Fool analyst Rex Moore was at the conference, and chatted with Stratasys engineer Jim Comb. In this installment of our series, Jim explains the differences between Stratasys -- after its merger with Israel's Objet -- and other 3-D companies.

Editor’s note: To clarify the disclosure position outlined below, The Motley Fool owns shares of 3D Systems through both our Supernova and Pro real-money premium services. In addition to the shares it owns, our Pro premium service has written a “covered strangle” options position on 3D Systems, agreeing when the trade was set up to buy more shares at a lower price, or to sell existing shares at a higher price – while maintaining the ability to close either obligation any time. Finally, 3D Systems is a recommendation in Stock Advisor, which is not a real-money service.

Rex Moore has no position in any stocks mentioned. The Motley Fool recommends 3D Systems and Stratasys. The Motley Fool owns shares of 3D Systems and Stratasys and has the following options: Short Jan 2014 $55 Calls on 3D Systems and Short Jan 2014 $30 Puts on 3D Systems. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.