Im sorry if this is a little late for you, but I like using mylar for stencils it holds up well and is reuseable but I am not sure if you can cut it on a plotter it is pretty thick although there are different thicknesses that can be purchased. I used to use a stencil burner I had bought from an art store it looks like a soldering iron with a pen tip but to cut a lot of stencils would be tedious work. Your best bet world be to pick up some mylar and try to cut it most likely with a 60 degree blade.
