A method includes receiving a layout file for a reticle used to pattern a first die location in a computing apparatus, the layout file defining a plurality of kerf features. A flare map calculation area for the first die location covering at least a portion of a kerf region surrounding the first die location is defined in the computing apparatus. Features in the layout file into the region corresponding to the flare map calculation area that are associated with the patterning of die locations neighboring the first die location are copied in the computing apparatus to generate a modified layout file. A flare map of the portion of the kerf region included in the flare map calculation area based on the modified layout file is calculated in the computing apparatus.