An ink jet process is used to deposit a material layer to a desired thickness. Layout data is converted to per-cell grayscale values, each representing ink volume to be locally delivered. The grayscale values are used to generate a halftone pattern to deliver variable ink volume (and thickness) to the substrate. The halftoning provides for a relatively continuous layer (e.g., without unintended gaps or holes) while providing for variable volume and, thus, contributes to variable ink/material buildup to achieve desired thickness. The ink is jetted as liquid or aerosol that suspends material used to form the material layer, for example, an organic material used to form an encapsulation layer for a flat panel device. The deposited layer is then cured or otherwise finished to complete the process.

Examples disclosed herein relate to device. The device includes a substrate, a plurality of adjacent pixel-defining layer (PDL structures disposed over the substrate, and a plurality of sub-pixels. The PDL structure have a top surface coupled to adjacent sidewalls of the PDL structure. The plurality of sub-pixels are defined by the PDL structures. Each sub-pixel includes an anode, an organic light emitting diode (OLED), a cathode, and an encapsulation layer. The organic light emitting diode (OLED) material disposed over the anode. The OLED material extends over the top surface of the PDL structure past the adjacent sidewalls. The cathode is disposed over the OLED material. The cathode extends over the top surface of the PDL structure past the adjacent sidewalls. The encapsulation layer is disposed over the cathode. The encapsulation layer has a first sidewall and a second sidewall.