When Greg Mark takes his 3D printer to VCs he gets blank stares. The Boston-based CEO of Markforged, a 3D printing company that specializes in printing carbon fiber and metals, has found that few of them could understand his technology. That’s why he turned to Microsoft Ventures, Posche, and Siemens-backed Next 47 for his next $30 million for his Series C. These industry-backed VCs… Read Morevia Tingle Tech