An improved packing member (230) includes a rigid interior portion (736) enclosed by a resilient exterior portion (734). The exterior portion is physically adapted to generate a force in response to, and opposing, the motion of an elongate object (808) thereover. The generated force advantageously increases in magnitude as the object moves across a packing member. In some embodiments, a frame (200) receives the improved packing members (230). In one embodiment, the frame (200) comprises two vertical side portions (220A, 220B) that receive one or more of the packing members. The frame advantageously includes a variable-positioning element (232A), so that the packing members are freely positionable along the height of the vertical side portions. In conjunction with the improved packing member, the variable positioning element enables embodiments of the present invention to be used with multiple object diameters/geometries.