Hatch patterns are commonly used in graphics software to highlight distinct areas of a map or drawing. There are three general techniques for filling in polygonal areas on a software canvas: * flood with a single defined colour - currently this method is supported by the Tk canvas. * fill with tiled raster image, and * fill with repeated vector pattern This page is dedicated to the discussion of the repeated vector pattern. Official http://docs.autodesk.com/ACD/2010/ENU/AutoCAD%202010%20User%20Documentation/index.html?url=WS73099cc142f4875513fb5cd10c4aa30d6b-7e57.htm,topicNumber=d0e368209%|%Documentation%|% from the Autodesk website for the popular commercial hatch definition format. <>GUI | Graphics