A piston ring, and in particular a compression piston ring, has a running face, upper and lower flank regions, an inner circumferential surface and a joint, wherein at least the running face is provided with at least one wear-resistant PVD or CVD layer, wherein the PVD or CVD layer extends at a predefinable layer thickness across a circumferential length of more than 95%, but less than 100% of the piston ring, and defined circumferential sections are designed in a layer-free manner in the region of the joint.