Suggestions for flat bed plotter playtime:

Try one of those conductive marker pens on some acetate. It would be a lot easier to remap a membrane KBD at the flex circuit level to than using an expensive hardware controller . . .

. . . try it on blank FRP for prototyping PCBs

my favorite:

Test a paint marker for plotting etch resist on copper clad FRP.

_____ if the Y axis travel and pressure are sufficient, the marker might be self-priming throughout a plot

_____ if the paint marker is fine enough (they're trimmable) and resolution is good enough, drill positioning holes in the pads might be etched.

_____ with pin-hole registration, you ought to be able to do double sided board prototyping

HEH!!!!! [] ]'>