Sight lines can also refer to the
line which, if
crossed, someone in the
audience will be able to see you (as an
actor, or
techie). If
flats are placed
judiciously, then the sightlines
offstage will be minimal, meaning that you can walk around
backstage without worrying about whether you can be seen by the
audience or not. However, due to some
set designs, white lines have to be
painted or
taped on the
floor to show
actors where they can and can't go when not
onstage (of course, the
techies know this instinctively - they don't need the lines!)
If you're after any other theatre tech information, then do take a look at '
Everything you ever wanted to know about theatre tech, but were afraid to ask'