A single product can carry both a utility patent, which protects how it works, and a design patent, which protects how it looks, and pursuing both is often the shrewdest protection strategy a company can adopt. This article maps the two statutory regimes and the exact circumstances in which concurrent protection is available, then explains the functionality bar that separates a protectable ornamental design from an unprotectable functional one. It works through obviousness-type double patenting as it operates across patent types, including the Carman Industries cross-reading standard, the patentee-favorable two-way test, the Section 121 divisional safe harbor, the common-ownership requirement, and the mechanics and hidden costs of terminal disclaimers. It contrasts the very different infringement tests and damages rules of each regime, including the Section 289 total-profit remedy after Samsung v. Apple and the overhaul of design-patent obviousness in LKQ v. GM. A fully worked hypothetical ties the doctrines together, and a practitioner FAQ closes the piece.