Poly-siloxane material may be used to form an insulating structure in an organic light-emitting device (OLED). In addition to the insulating structure, an OLED may have an electro-luminescent organic layer separated into light-emitting elements, e.g., display pixels, arranged between electrode layers. A voltage applied across the electrode layers causes the device to emit light. One type of insulating structure may be a bank structure formed from a thin sheet of poly-siloxane with apertures corresponding to the display pixels. Pixels may be formed with the deposit of one or more layers of organic material into the apertures. Another type of-insulating structure may be one or more insulating strips, which may separate an electrode layer into electrode strips during construction and/or insulate electrode strips while the OLED is in operation.