Homebrew PCBs

I must admit I enjoy reading this group, not the least of my enjoyment from the diversity of ideas on how to make pcbs at home.  I am a toner transfer practitioner which suits me fine.  I have done photoresist many moons ago when I had access to the coating chemicals.  

Currently I am working on building a 3D plastic printer (google reprap if curious) and it occurred to me that printing plastic (or a meltable material that would resist etchant) on a pcb would be yet one more way to put down etch resist...any I won't bet someone has not already tried it.  Now you won't catch me trying it but...any thoughts?