An electronic device may have a housing. Electrical components such as a display and other circuitry may be mounted in the housing. The housing may have portions that move with respect to each other such as a lid that rotates relative to a base. A flexible printed circuit may have metal lines that couple components in one portion of the housing to components in another portion of the housing. As the housing portions move with respect to each other, the flexible printed circuit bends. Reliability may be enhanced for the flexible printed circuit by providing the metal layer that forms the metal lines with upper and lower coating layers. The coating layers may be formed from metal with a higher Young's modulus than a metal core in the metal layer. A slot may be formed along the length of the flexible printed circuit to help increase the minimum bend radius exhibited by the flexible printed circuit. Upper and lower metal shield layers may be provided above and below the metal traces.