Surface roughness can also affect the adhesive strength. Surfaces with roughness on the scale of 1–2 micrometres can yield better wetting because they have a larger surface area. Thus, more intermolecular interactions at closer distances can arise, yielding stronger attractions and larger adhesive strength. Once the roughness becomes larger, on the order of 10 micrometres, the coating can no longer wet effectively, resulting in less contact area and a smaller adhesive strength.