Apple famously uses its $80b cash hoard to buy exclusive supply arrangements for its most popular products, and the MacBook Air's unibody frame is apparently no exception. DigiTimes says that Apple's demand on Catcher Technology, the highest-capacity unibody producer, has forced other manufacturers to save aluminum unibody construction specifically for their premier models while turning to other methods for cheaper, high-volume machines. One option reportedly under consideration involves a hybrid design with aluminum stamped to plastic interiors, to preserve the premium metal look and feel. As for lower-end laptops, this report builds on similar news from August saying that plastic and fiberglass would likely be used. We've reviewed a number of ultrabooks this fall, and while unibody construction provides a very solid feel (like we saw on the Lenovo U300s), it's not the only piece of the puzzle. Hopefully laptop makers will use this as an opportunity to continue innovating with new designs rather than rehashing the MacBook Air.