Ok, litteraly I:
-> design circuit in Cadsoft's Eagle
-> print it (reversed image) to spam paper*
-> cut a piece od PCB to the right size and clean it up so the copper is nice and shiny
-> put the printed circuit over the pcb and apply heat and pressure** so that it sticks together
-> cool in water until paper gets wet, then just peal it off.
-> the toner remains burned to copper and is ready to be thrown in acid (or whatever you use, I prefer iron-III-chloryde as it's least dangerous to use)
And that's it. The accuracy limitation is defined with your laser printer dpi rating, nothing else.
- I refer to spam paper as the spam commercials that you get in your mailbox (no, not email, but real mail), I find the ones from Hoffer or Spar (EU people know it) the best as the paper is thin and smooth. That's the reason why ordinary white paper is nos suitable - the toner just holds on it too well and won't get off to copper nicely
** you can use a heat iron for some minutes, or, for best performance use photo laminator, I use one like in this photo, costs about 15?.
Regards,
Peter