A medical bandaging product, including a sleeve formed of moisture-impervious material and sealable to prevent entry of moisture, and a medical material positioned in the sleeve and sealed therein against entry of moisture until use. The medical material is a substrate having two marginal areas of relatively lower modulus yarns and/or a more open knitted structure to provide reduced abrasion against the skin. A reactive system on the substrate remains stable when maintained in substantially moisture-free conditions and hardens upon exposure to sufficient moisture to form a rigid, self supporting structure. A soft, flexible protective material covers at least one of the major faces of the substrate along its length to provide a cushioning barrier between the substrate and the skin of a patient when the material is in use.