Cirqoid is circuit board milling machine capable of isolation milling two sided circuit boards, drilling holes, dispensing solder paste, and populating the board with SMD components. The minimum width of trace you can reliably produce with Cirqoid is 0.2mm (8 mils). It’s the same for the clearance (distance between neighboring traces).
Gerber Files – how to produce from Eagle CAD
Notes on using cirQWizard and Cirqoid