Drying property is a vital subject to be considered when assessing coating materials, irrespective of whether the coating is to be applied manually or in an automatic process.

As a general rule coatings with volatile solvents dry from the outside inwards.

The substances are allocated to different categories in order to define the progressive drying process of different coating materials.

Surfaces that appear dry on the outside but have not dried all the way through can be easily damaged if mechanical stress is applied.