Knife Pleat

A knife pleat is a type of sharply pressed pleating, especially in a skirt or kilt, in which all of the folds are turned in one direction, with each pleat being three layers of fabric thick. Knife pleats are named for their sharp edges. They add fullness without bulk especially when they are stitched down at the top. The unidirectional folds produce a flat front that does not spring out from the waistband. 

Versus' Autumn/Winter 2010 collection was full of knife pleated skirts;

A knife pleated dress from Issey Miyake's 132 5 collection, on  display at the  Galerie Kreo,  Paris.

Knife Pleats: Giambattista Valli S/S 2009

Knife Pleats: Miu Miu Autumn/Winter 2008/9

Knife pleats: Ives Saint Laurent Spring/Summer 2010;