Embodiments of the present disclosure relate to an apparatus and methods for forming arrays of EL devices and forming the EL devices with overlapped mask plates. The methods utilize overlapping a first mask plate and a second mask plate to form a mask arrangement having first apertures of the first mask plate overlapped with second apertures of the second mask plate forming one or more opening areas. A material is evaporated through the mask arrangement such that layers of the material are formed in a device area of the EL devices. The device area of each of the EL devices corresponds to the opening area of the mask arrangement of the first mask plate and the second mask plate. The method described herein allows for a higher density of the EL devices and creates a smaller deposition area due to the opening area of the mask arrangement.