General Electric has agreed to acquire two European 3-D printing companies for a combined $1.4B, tapping into manufacturers’ growing demand for digital technologies. Both Arcam (OTCPK:AMAVF) and SLM Solutions (OTC:SLGRF) make machines that can print metal parts used in aircraft components such as turbines. 3-D printing “will drive new levels of productivity for GE including a wide array of additive manufacturing customers, and for the industrial world,” CEO Jeff Immelt said in a statement.