This is the method of cutting timber to a special dimension; feather edge is traditionally used for exterior cladding. The feather edge cladding protects the structure from elements. The design of feather edging means that one part is thick and then tapers down to a thin edge. This allows near double the area to be achieved from the same volume of timber. Feather edging is very popular with old barns; as is waney edge board cladding.