Abstract: A clamping apparatus is provided for holding thin flexible printing plates, especially Mylar printing plates, in position on a press cylinder. A metallic rigid clamp body is provided which is attachable to the press cylinder in a gap or groove formed between facing ends of plate supporting shims and/or edges of a groove formed in the press cylinder. A pivot bar having a serrated clamping edge is pivotally supported in the clamp body for cooperation with a fixed facing clamping surface of the clamp body to clamp the leading edge of the "Mylar" plate. A "Mylar" spring is provided for providing a continuous light biasing force on the pivot bar in the clamping direction. The clamping action of the pivot bar is by way of camming action and engagement of the serrated surface into the "Mylar" or other printing plate material, such that movement of the plate in a direction out of the clamping space tends to increase the clamping force of the pivot bar.

Abstract: A permanent magnet holding plate comprises a thin base sheet of stiff, nonmagnetic material with a multiplicity of pole pieces made of strips of magnetic material extending across the base plate but separated from one another, and strips of compressible permanent magnet material located in the spaces between the pole pieces and in intimate contact therewith and polarized to induce magnetic poles of opposite polarity in successive pole pieces. In a preferred embodiment, the base plate is curved to form a magnetic holding saddle and the pole pieces and permanent magnet strips are transverse to the curvature of the plate.