This attribute determines the line width used when drawing each
element of graphical output produced by a PlotPlot. It takes a
separate value for each graphical element so that, for instance,
the setting "Width(border)=2.0" causes the Plot border to be
drawn using a line width of 2.0. A value of 1.0 results in a
line thickness which is approximately 0.0005 times the length of
the diagonal of the entire display surface.
The actual appearance of lines drawn with any particular width,
and the range of available widths, is determined by the
underlying graphics system. The default behaviour is for all
graphical elements to be drawn using the default line width
supplied by this graphics system. This will not necessarily
correspond to a Width value of 1.0.