How about adding horizontal lines to denote the boundaries?
Could use one of these methods:
http://peltiertech.com/Excel/Charts/...orzErrBar.html
http://peltiertech.com/Excel/Charts/...orzSeries.html
best wishes
--
Bernard Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme


"mrsatroy" wrote in message
...
I am working in a microbiology lab and am plotting on a bar chart zone
size
versus number of isolates. The size of the zone determines whether or not
an
organism is sensitive, intermediate or resistant to an antibiotic. I would
like to be able to illustrate on the graph which area on it pertains to
resistance/intermediate/sensitive. At the moment I just have a list of the
zone sizes on the Y axis but it would be great if there was a visual
representation on the chart area of where the different interpretations
began
and ended, inother owrds to almost divide the graph into 3 areas with the
columns in each area. Hope this makes sense!
--
mrsatroy