As critical dimensions (CDs) approach (lambda) /2, the use of optical proximity correction (OPC) relies heavily on the ability of the mask vendor to resolve the OPC structures consistently. When an OPC model is generated the reticle and wafer processing errors are merged, quantified, and fit to a theoretical model. The effectiveness of the OPC model depends greatly on model fit and therefore consistency in the reticle and wafer processing. Variations in either process can 'break' the model resulting in the wrong corrections being applied. Work is being done in an attempt to model the reticle and wafer processes separately as a means to allow an OPC model to be implemented in any mask process. Until this is possible, reticle factors will always be embedded in the model and need to be understood and controlled. Reticle manufacturing variables that effect OPC models are exposure tool resolution, etch process effects, and process push (pre-bias of the fractured data). Most of the errors from these reticle-manufacturing variables are seen during model generation, but there are some regions that are not and fail to be accounted for such as extremes in the line ends. Since these extreme regions of the mask containing the OPC have a higher mask error enhancement factor (MEEF) than that of the rest of the mask, controlling mask-induced variables is even more important. This paper quantifies the reticle error between different write tools (g-line vs. i-line vs. DUV lasers) and shows the effects reticle processing has on OPC model generation. It also depicts which structures are susceptible to reticle error more than others through reticle modeling and SEM images.