DLC stands for Diamond-Like Carbon; carbon layers or coats with specific properties: great hardness, high wear resistance, very low friction (e.g. vis-à-vis steel) and excellent chemical resistance. By integrating other elements into the hydrocarbon network of a DLC coat, a wide range of changes to the wetting behaviour of the coats can be achieved. DLC coats are primarily used in abrasion-proof adhesive coats and non-stick coats. Nowadays, DLC coats provide a group of substances from hard, wear-resistant and very low-friction types to Teflon-like coats, suitable for a great variety of technical applications. Generally, carbon-based coats are classified in diamond coats, hydrogen-free ta-C coats, hydrogenous DLC or a-C:H coats, metallic and thus conductive Me-DLC or Me-C:H coats, and DLC or a-C:H:X coats modified with non-metallic elements. By means of plasma coating in PACVD processes using acetylene C2H2 as a process gas, DLC coats can also be applied to plastic substrates without excessive thermal load.