Totally agree with JAZZ .
If that's going to be pen only there is no point to mess with ballnuts and screws. Belt is defenetly a way to go. I wouldn't drive it directly but made some reduction, but of course direct drive will work as well.
eg belt 3M pitch belt driven with 15 tooth pulley gives you 45 mm of axis movement per revolution of driving pulley. Reducing it further 5x gives you 9mm/rev. Driving it with stepper (after reduction) @1/2 step (400 steps/rev) gives you 0.0225mm resolution. I think its enough for your boat drawing or even for cutting
Driving it directly with 15 tooth pulley @1/2 step will give you 0.1125mm resolution
Just some example calculation -hope it helps