A braided sleeve (10) is comprised of a first material in monofilament form (11) characterised in that it has high modulus of elasticity and is capable of taking a resilient set. The first material is interbraided with a second material in filamentary form (12) which is chosen to impart a property to the sleeve according to its intended end use. The sleeve is further processed to introduce a series of resiliently set radially projecting according folds or pleats (14) which extend in a series lengthwise of the product and may be in groups with intervening spaces in which no corrugations are formed. The braid allows for radial expansion and contraction so that is resiliently conforms to the shape of an elongated substrate which may have irregularities in its cross section and further allows for appreciable axial elongation and expansion so as to protect a substrate having the property of axial extension and contraction.