It takes about 200 hours to get from a blank piece of wood to a violin "in the white" or without varnish. After that, varnish is applied over the course of several days to weeks. It is not finished yet, then you have to "set up" an instrument by putting on the fingerboard, nut, saddle, bridge, pegs and strings. Even then, a new instrument needs time to adjust and stretch under the pressure of the strings.
What kind of wood do you use?
The top is always made of spruce because it is relatively soft and vibrates well. The back is typically made of maple, either one piece or two pieces mirrored and seamed together. Maple is stronger and gives support to the sound and playability of the instrument. The scroll is also made of maple. The fingerboard is made of ebony.
What determines the quality of an instrument?
The quality of an instrument depends on several factors. First is its playability and tone. Playability refers to how responsive the instrument is, how does it feel in your hands, how easy is it for you to get the sound you want out of it. When it comes to tone, it gets even more subjective. Different people hear and like different qualities. In general, some things to listen for are tinniness, brightness, fullness and, of course, wolf notes. After playability and tone, we consider the aesthetic qualities. How clean are the lines, are the f-holes nicely shaped and symmetrical, does the scroll look balanced? Do you like the type of fittings and pegs? How well is the varnish applied? All these craftsmanship issues contribute to the quality of an instrument.