The outer contour of a new violin, one of the more important aspects of the instrument, is designed by the violin maker, and today the outlines of the old masters' violins are usually used. Different methods of violin making include using an inside mould, an outside mould, or building "on the back" without a mould.
The "inside mould" approach starts with a set of plans, which include a drawing of the outer shape of the instrument. From these plans a template is constructed, which can be made from thin metal or other materials, and is a flat "half-violin" shape. The template is used to construct a mould, which is a violin-shaped piece of wood, plywood, MDF or similar material approximately 12 mm or 1/2" thick.
Around the mould are built the sides (or ribs), which are flat pieces of wood curved by means of careful heating. The completed "garland" of ribs, blocks, and linings is removed from the mould to allow attachment of the separately carved top and back. When the body is complete, the neck, which is carved out of a separate piece of wood (usually maple), is set in its mortise to complete the basic structure of the instrument, after which it is varnished.
Vital to the sound and playability of the instrument is setup, which includes adjusting the neck angle if needed, fitting the pegs so they turn smoothly and hold firmly, dressing the fingerboard to the proper scooped shape, fitting the soundpost and bridge, adjusting the tailgut and installing the tailpiece, and stringing up. A removable chinrest may be put on at this time.
Then the instrument begins the "playing-in" process, as its parts adjust to the string tension. The sound of a violin is said to "open up" in the first weeks and months of use, a process which continues more gradually over the years. However, this process may be aborted at some point. If you put a violin to storage and pull it out a while later, you will notice when you first play that the violin has lost volume (this is a very common sign of violin inactivity), and loss of quality (this is in more severe cases of inactivity). If you put a violin into storage, pull it out a while later, and play it for a few weeks, you will notice the violin's sound start to open up again.