Abstract: A printing or embossing unit has at least two cylinders (1, 2). Of the latter, one working cylinder (1) carries at least one printing or embossing stencil (14) on its circumference, in order to emboss or to print, with the aid of the said at least one printing or embossing stencil (14), a web (5) made from a flat material which is conveyed between the said working cylinder and a back-pressure cylinder (2). The embossing stencil (14) extends in each case only over part of the circumference of the working cylinder (1) and is held on the working cylinder (1) with the aid of a fastening device (12, 13, 15). The working cylinder (1) is provided in its interior with a heating device. The fastening device (12, 13, 15) has at least one clamping ring (15) which acts on the circumferential edge (16) of the printing or embossing stencil (14) and clamps against the working cylinder (1).