PSTricks optionsWhen language pstricks is selected (the default), permissible
key-value pairs include all those for similar PSTricks objects.
For example, a polygon might have the options
[linewidth=1pt,linecolor=blue,fillcolor=cyan]
Sketch merely passes these on to PSTricks without
checking or modification. Option lists are always optional. A
missing options list is equivalent to an empty one [].
When a polygon has options for both its face and its edges, and
the polygon is split by the hidden surface algorithm, sketch
must copy the edge options to pslines for the edge segments and
the face options to pspolygons. Options known to sketch
for purposes of this splitting operation include arrows,
dash, dotsep, fillcolor, fillstyle,
linecolor, linestyle, linewidth, opacity,
showpoints, strokeopacity, and transpalpha.