This part of ISO 9117 specifies a method for determining whether coatings, including those produced using multi-coat systems, have reached various stages of drying (see Table 1). 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 drying stages 4 to 7 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.