A soundpost patch being fitted. The bumpers on the sides are used to align the patch during fitting. An old crack, filled with dirt and no longer closed. Cracks like this can "creep", becoming more dangerous with time. | 
The patch being glued. A cast (or counterform) of the violin's top must be made to ensure that the top won't be distorted by the clamping process.  After cleaning and closing the crack, the restored area is both less visible and more stable. | 
The completed patch, prior to final scraping. |