Unpressed Pleats
Unpressed pleats are softer, as you’d expect, than their pressed counterparts and have a more rounded edge. Unpressed pleats are also usually wider, creating a more delicate silhouette than cartridge, pressed or decorative pleats.
Vent
Vent does not here refer to an explosion of hot air or emotions. In garment terms, a vent serves a similar purpose to a slit. They are often in the back seam of a jacket, where they have been inserted to let the shape ‘breathe’.