Fan Darts are a gorgeous Vintage trick I just adore! When you have a pattern which has a plain old Dart in the back, why not separate it to make several Darts, or Fan Darts?
Firstly, measure the original Dart then divide that measurement into the amount of Darts you would like, as above.
Using the positioning of the original Dart, reduce the size, then draw in two more. Ensure they are evenly placed. When sewn up, this will produce a series of small Darts, often called Tucks, instead of one larger and slightly clunky Dart.
Alternatively, you may also ’tilt’ the top of the Darts as illustrated in the final picture. This should be done by eye so as to ensure it will look good when worn however; measure roughly 3cm- or just over 1″- away from the original tip of the new, smaller Darts then re-draw the Darts as shown. When sewn up this will produce an enormously attractive fan of small Darts across the back of your bodice.
I have just made up- for myself, heavens, will wonders never cease!- Butterick 5747 and have included Fan Darts in the back of the bodice as described above. I think this simple trick can really add to the overall look of the Dress, and it is a fabulous way of adding in some more shaping if necessary.