Ironing rasps are used for selectively dropping the middle of a flat surface away leaving proud areas that can be carved or shaped - think relief carvings, pie crust tabletops, or areas to be inlaid with veneer.
After hogging away the majority of the waste with forstners, routers or gouges, the rounded ironing rasp will gently and efficiently gnaw away remaining material and the flat version (almost flat, they still have a very slight radius) will crisp up corners, work larger areas and produce a more level and even background.
The necks are cranked to leave room for your fingers, the back of the tool is unstitched and can be used to lightly rest the fingertips of the opposite hand.
Flat (ish) Version
20mm wide x 80mm long x 3mm thick