Coating adhesion refers to the ability of a coating, such as paint or varnish, to stick firmly to a surface. This property is crucial for ensuring that the coating remains intact and performs well over time. Factors affecting adhesion include surface preparation, the type of coating used, and environmental conditions. Good coating adhesion prevents issues like peeling, flaking, or bubbling, which can compromise the appearance and durability of the finish. Proper techniques, such as cleaning and priming the surface, can enhance adhesion. Testing methods, like the cross-hatch test, are often used to evaluate how well a coating adheres to a substrate.