Today a colleague of mine could not plot a polyline at the desired lineweight. We tried different layer with the colour changed to see if was the plot style interferring. Tried turning off scale lineweights. Tried overriding the lineweight on the object itself. Tried a new plot style.
After all these attempts it occured to me that the polyline thickness might have a impact on the lineweights and it does.
Altering the polyline global width to 0 meant the lineweight now plotted correctly.
We had new printers in today, they were Xerox machines. They are quiet neat but not particularly useful when printing from AutoCAD. The reason why? Because for some reason AutoCAD and the Xerox drivers do not play nice with each other when printing with transparency.
When printing with transparency checked in the plot dialog the Xerox printers just print a small section of the page, about a 5th. Without that checked all is good.
The reason seems that AutoCAD prints vectors normally but when transparency is checked is prints rastors. For some reason this does not play well with the Xerox.
On this post on the second page are some settings but they are not on my driver version. I will investigate some options and update if I find a solution with the newer drivers.