G'day Clansfolk,

I'm right outside my instrumental expertise here, but commercially made 'fretted' violins were quite common. I have seen a couple of old "Manby" patent ones - which have indented, rather than raised, frets ... about 2 mm wide and less than 1 mm deep.

The instruments are otherwise standard violins and have normal strings, tension, bowing characteristics &c. My friend, who played one for some time, eventually put is aside - in favour of a nice fiddle in the Guanarius style (but that's another story). He didn't mind the frets much - except when he wanted a nice glissando.

Historically, most Manby fiddles ended up with new - fretless - fingerboards when their owners became confident without the 'frets' and skillful enough to need the techniques allowed by a fretless fiddle.

Regards,

Bob Bolton