Iron Man 2 opens today! Are you excited? Really? Huh. Well, keep reading anyway. You know someone’s gonna drag you into a showing.

On screen, with all those suits whirling into place, you’d probably assume that the “costumes” are merely virtual. Actually, they’re not: Maybe the most cutting-edge facet of Iron Man 2‘s production was the real-life fabrication of the suits. Using 3-D printers, the film’s production company, Legacy Effects, was able to have artists draw an art concept–and then physically make that concept in just four hours.

The “Eden” printers, which are made by Objet, work by using an inkjet cartridge to print a layer of powdered plastic, which is then fused with UV light. Each layer is just microns thick, and the product gets printed from the bottom up. Here’s video of the process, though not an actual Iron Man costume:

The product emerges completely finished. All you need is some paint. Basically, if Tony Stark was real, he wouldn’t be sitting around in a tool shop. He’d be clicking on a CAD program, and then kicking his feet up as his suit was printed.