Abstract: A melt-embossed polymer film with primary parallel grooves on one surface and secondary parallel grooves on the other surface such that the combined tapes of the grooves is at least substantially equal to the film thickness, the two sets of grooves being located at an angle to each other of not less than 30.degree., is stretched at right angles to the direction of the primary grooves by a small amount to give a perforate product which can be formed into strips tearable longitudinally or transversely and thus useful as a vapor-permeable substrate for adhesive-coated tape.

Abstract: A non-woven fabric is produced by stretching the film with on one surface a regular pattern of raised areas such as spaced hexagonal bosses and on the other surface a plurality of parallel grooves. Stretching is carried out in the groove direction. Preferably the polymer is a mixture of incompatible polymers so that on stretching a fibrous structure is formed. The film can be produced by melt-embossing. The stretched non-woven fabric may be coated with various adhesives to provide a tape useful in a medical context.