You should have just gotten a message describing the total lengths of plots you've sent this semester. You should limit your total plot length to 20 feet. If you have exceeded this figure, and you still don't have a plot to turn in, plan to make only one plot only -- for turning in.
Note that the plotter use statistics does not take into account plots that are bad due to toner problems. Part of the $5/foot charge we use for clients takes this into consideration (they are not charged for bad plots that are the fault of the plotter). Though we're not using such a system with classes you can assume that plots that are bad through no fault of your own should not be considered.
Unfortunately we get no University budget to operate the plotter -- we're supposed to pay for it through contracts. This is not possible. You can see why we must be concerned with excess plotter use.
I appreciate your help in keeping our costs down.