Inverse Lithography Technology (ILT) is a rigorous approach to determine the mask shapes that produce the desired on-wafer results. In this paper, we briefly describe an image (or pixel))-based implementation of ILT in comparison to OPC technologies, which are usually edge-based. Such implementation is more computationally scalable and avoids laborious segmentation script-writing, which becomes more complex for newer generations because of complicated proximity effects. In this paper, we will give an overview of ILT, present some simulation and wafer examples to demonstrate the benefit of ILT, clarify common myths about ILT, discuss and show examples to illustrate the impact in every step of the mask making process. Specifically, studies done with several leading mask shops around the world on mask manufacturability (including data fracturing, writing strategy and writing time, mask inspection), will be shown.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.