This attribute determines the character size 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 "Size(title)=2.0" causes the Plot title to be drawn
using twice the default character size.
The range of character sizes available and the appearance of the
resulting text is determined by the underlying graphics system.
The default behaviour is for all graphical elements to be drawn
using the default character size supplied by this graphics
system.