A plurality of corrugated plates are arranged in parallel relationship with corrugations in adjacent plates extending in a criss-crossing pattern to form a packing element for a heat exchange or mass transfer column. The plates are spaced closer together by providing reliefs in adjacent plates at the points of intersection between the criss-crossing corrugations. The reliefs allow the corrugations on the adjacent plates to extend into each other to reduce the spacing between the plates. The reliefs may be in the form of apertures or recesses.