The default value for the aperture is 256. The minimum value is 1 stroke. The maximum value depends on the raster that is used but can never exceed 9999. For rasters that use 2 bytes or less in a vertical line (i.e. 1 or 2 lines of 7 drops per line), the maximum value of 9999 can be used. For rasters that use three bytes in a vertical line (i.e. 3 lines of 7 drops per line), the maximum value is 8192. For rasters that use four bytes in a vertical line (i.e. 3 lines of 9 drops per line) and FreeForm, the maximum value 6144