Is there a trick to using this technique for shading part of the plot area
for a bar chart? I've had a couple of goes using the info from the link you
provided for line graphs, but had no luck so far.
My chart has 20-ish bars, with a y-axis that's 0-100% in 10% intervals. How
can I shade the 40-70% plot area? Got the feeling I might be missing
something obvious...