On a cold March day in Chicago, I crossed the heavily designed campus of IIT. I had just given a talk (on this very book, then in progress) and had enjoyed coffee in the dramatic campus center designed by architect Rem Koolhaas (with the Green Line train running through it). But my hosts from the Humanities department had also arranged for me to drop in to see the fabrication and rapidprototyping lab, the Idea Shop at the University Technology Park.1 In one empty room we looked into, with schematic drawings on the walls, a large tabletop machine jumped to life and began whirring, as an arm with a router moved into position. A minute later, a student emerged from an adjacent room and adjusted something on the keyboard and monitor attached by an extension arm to the frame for the router, then examined an intricately milled block of wood on the table. Next door, someone was demonstrating ﬁnely machined parts in various materials, but mostly plastic, wheels within bearings, for example, hot off the 3D printer. At the table where he stood, a box full of colorful 3D-printed prototypes or experimental objects (it was hard to tell the difference just by looking) was laid out, like interesting toys. Most had been built up out of melted polymers squirted onto a base, extruded according to the speciﬁcations of CAD (computerassisted design) and STL (stereolithography) ﬁles.