Abstract: A packer element for a blow-out protector comprising a body of an elastomeric packing material interposed between a pair of opposed reinforcing plates wherein a slight pre-load compression is imparted to the working surface with which the packer element seals off the annular space around a drill pipe. The pre-load compression is achieved by forming the packing body with top and bottom surfaces which diverge in the direction of the working surface and compressing the packing body between the reinforcing plates such that in the blow-out protector the reinforcing plates sit in substantially planar parallel relation. By building pre-load compression into the packer element, it has been found that the useful life of the element is enhanced.