Gathering user feedback on provisional design concepts early in the design process has the potential to reduce time-to-market and create more satisfying products. Among the parameters that shape user response to a product, this paper investigates how design experts use sketches, physical prototypes, and computer-aided design (CAD) to generate and represent ideas, as well as how these tools are linked to design attributes and multiple measures of design quality. Eighteen expert designers individually addressed a 2 hr design task using only sketches, foam prototypes, or CAD. It was found that prototyped designs were generated more quickly than those created using sketches or CAD. Analysis of 406 crowdsourced responses to the resulting designs showed that those created as prototypes were perceived as more novel, more aesthetically pleasing, and more comfortable to use. It was also found that designs perceived as more novel tended to fare poorly on all other measured qualities.