A dart vanishing point forms a smooth transition from the dart intake to the garment surface.
If you look at a flat, unstitched dart, the vanishing point is very easy to find providing a point where all dart lines meet on the fabric surface. The position of the vanishing point is very important in dressmaking as it shapes raised areas on the garment, creating the appropriate three-dimensionally to accurately follow the human form. For example, on the front of a garment the dart vanishing point will radiate from the apex, which is the highest pint(s) on the bust.
To ensure a well-constructed dart, all darts are sewn form the widest intake moving towards the vanishing point(s). The dart stitch should transition smoothly at the vanishing point and not create any puckers or tension. The stitch should blend perfectly into folded edge, ending directly in the marked vanishing point transferred for your paper patterns. For best results, you should not backstitch at the vanishing point as doing so can distort this vulnerable area. For best results, simply tie the machine loose threads together to lock the stitch.