4 Check perpendicular:
Having decided where the new bridge will go I begin fitting it to the top. During this process the angle at which the bridge stands on the top is monitored. The finished bridge is held onto the violin top solely by the downward force of the strings. The center line of the edge of the bridge should bisect the angle of the string as it passes over the top of the bridge. If it does not, the pressure on the bridge feet will be concentrated at either their front or back edges. This changes the effective distance between the sound post and bridge foot, a change equivalent to a major soundpost adjustment.

Cutting the bridge to lean too far forward, towards the fingerboard, is a frequent flaw in bridge-fitting.

A correctly cut bridge appears to lean backwards, towards the tailpiece. On most instruments the back of the bridge will be roughly perpendicular to the top of the violin. A business card helps to gauge this as the bridge feet are cut to fit the top.