The Border Style is in the style of the Mercator Style like on these maps:

http://www.dancingshaman.net/blood/greyhawk1.jpg

http://mercator.csail.mit.edu/mercat...very_small.jpg

http://libweb5.princeton.edu/visual_...c1595-full.jpg

http://www.plancius.nl/maps/Worldmaps/images/w9.JPG