Abstract: The disclosure concerns an antibuckling apparatus for a lithographic plate or the like which is being cured in a UV post-curing apparatus. A source of UV radiation irradiates one surface of the plate as the plate is moved through a curing chamber along a predetermined path. An upper antibuckling device comprises a first pair of spaced elongated members which extend across the path of the plate and serve as a support for a plurality of upper antibuckling bars disposed between the radiation source and the upper surface of the plate. The antibuckling bars are disposed generally along the path of the plate but obliquely to the direction of the path, whereby the antibuckling bars do not interfere with irradiation of the entire width of the upper surface of the plate. A similar lower antibuckling device may be disposed beneath the plate on the side thereof not being irradiated.