A patterned conductive layer on a flexible substrate includes pads for mounting an array of LEDs, conductive strips, and conductive tabs that couple the conductive strips to the pads. The desired circuit configuration is created by removing select tabs by punching holes or otherwise piercing the flexible substrate at the location of the tabs. In some embodiments, the patterned conductive layer is arranged to permit each LED to be mounted in either of two mirrored orientations, and in some embodiments, the patterned conductive layer is arranged to permit a separation between LEDs that is not predefined by the pattern. In some embodiments, the unmodified patterned conductive layer is arranged to provide a parallel circuit configuration, and the modified patterned conductive layer is arranged to provide a series or series-parallel configuration.