Abstract: Hydraulic press including a frame with platens, at least one of which is carried or formed by a pressure plate structure adapted for transferring pressing force to an object between the platens, which press is adapted such that the pressure plate structure is substantially carried solely by horizontally adjustable supports mounted between the defining outer edges of such plate structure, such supports being positionally adjustable such that the surface of the corresponding platen assumes a predetermined shape during the pressing operation. The press suitably includes a mechanical mechanism for effecting the horizontal displacement in order to gain the desired positional adjustment of the supports.