A method for making a flexible OLED lighting device includes forming a plurality of OLED elements on a flexible planar substrate, wherein at least one of the OLED elements includes a continuous respective anode layer formed over the substrate, one or more organic light emitting materials formed over the anode layer, a cathode layer formed over the light emitting materials, and an encapsulating protective cover formed over the cathode layer. At least one of the OLED elements defines a continuous light region on the substrate, wherein the substrate and combination of OLED elements define an active light area. The active light area is bendable from a flat planar configuration to a bend configuration having a design bending radius. The thickness of the cathode layer is formed between a minimum thickness value and a maximum thickness value as a function of the size of the active light area and the design bending radius. An OLED in accordance with these aspects is also provided.