"Mid tone dip" is the Army Painter Strong Shade dip (although I never dip miniatures, the shade is liberally painted on with a thick brush):
http://www.firestormgames.co.uk/army-painter
The dip is much thicker than ink washes and flows into details better. It dries gloss so needs a coat of matt varnish. Some people hate the stuff, but I've found it gives fantastic results on all sorts of figures (from Warmachine to Napoleonics).