ooh thanks for the term, french darts
here it is...
simplicity.com
What is a “dart seam?”
A "dart seam" is long, curved dart that starts at the hipline of the side seam and extends diagonally to the bust. It is sometimes referred to as a
French dart. The pattern piece is designed so that the dart has cut edges, rather than center fold line. This makes the dart easier to sew and eliminates bulk. When the cut edges are brought together and the dart is stitched, the result looks like a seam with a point at the end. Follow the same marking and stitching procedures as for any other dart. A dart seam is usually pressed flat on one side, then open for most of its length and flat at the tip.
hmmmmm...