At least one dressing, such as a printing forme, is secured to the surface of a cylinder of a rotary printing press by securement devices. These securement devices are arranged in an axially extending channel on the surface of the cylinder. The channel is defined by at least one wall and by an opening directed toward the circumferential surface of the cylinder. At least one wall of the opening extends into the channel at an acute angle with respect to the cylinder circumferential surface. A deflection-resistant retaining device, provided with a first end and with a second end, is pivotably mounted in the channel. The first end holds an angled end of the dressing that is introduced into the channel opening. This first end is disposed remote from a bearing and pivoting point of the retaining device. A dimensionally stable bow, which has a portion that engages the wall of the opening that extends toward the channel at an acute angle, is situated in the channel.