Sub-resolution assist features for non-collinear features are described for use in photolithography. A photolithography mask with elongated features is synthesized. An end-to-end gap between two features if found for which the ends of the two features facing the gap are linearly offset from one another. A sub-resolution assist feature is applied to the end-to-end gap between the elongated features, and the synthesized photolithography mask is modified to include the sub-resolution assist feature.