A while ago a few readers requested a picture of the lap seam, as referred to in my feature on Pogson & Davis, tailors of Mayfair. Apologies this has taken so long, but here they are.
The lap seam is a decorative technique that creates an overlap of material up the side seam of a pair of trousers. Traditionally it is more formal rather than less. The second picture, below, shows how the seam folds into the trouser pocket.
Original post here: https://permanentstyle.blogspot.com/2009/07/decorative-lap-seam-pogson-davis.html