1. A method of assigning a subpath attribute to a subpath in a drawing, including: editing the drawing to combine a set of two or more previous subpaths into a current subpath, wherein each previous subpath is associated with a previous subpath attribute; determining for each previous subpath attribute the total length of the previous subpaths having that attribute; determining the previous subpath attribute associated with the greatest total length; assigning to the current subpath the previous subpath attribute associated with the greatest total length; and displaying the edited drawing.