An important challenge for Organic Light-Emitting Diodes (OLEDs) manufacturing is the patterning method of the organic materials used for different colors. In this talk, a Large-Area wet Micro-Printing (LAMP) technique is proposed and demonstrated for organic device patterning. A printing plate is first prepared by surface engineering so that a designed surface energy pattern is achieved. The printing plate is then coated with "ink," brought into contact with the device substrate, and the "ink" is transferred. With this approach, the red (R), green (G) and blue (B) sub-pixel arrays needed in a full-color display can be printed in three successive steps, one step for each color. Both single-color pixel arrays and R, G, B sub-pixel arrays have been patterned as a demonstration of the feasibility of this method. The technique has the potential advantages of low-cost and high-throughput and it avoids some of the practical problems associated with the design and operation of an ink-jet apparatus.