ISO 9117-5:2012 specifies a method for determining whether coatings, including those produced using multi-coat systems, have reached various stages of drying. Furthermore, it allows the drying speed to be assessed.
In the case of plastic coatings, it is only possible to determine to a limited extent whether the later stages of drying have been reached, as the elasto-plastic behaviour of these coatings cannot be evaluated on the basis of a temporary visible change in the coating surface.