There are four different systems:
Physical drying: The solvents evaporate. Physical drying is accelerated by higher temperatures and air speeds as good as with radiation drying. Physically dried films remain solvent.
Oxidative drying: Complete hardening is by means of absorbing oxygen. The hardening process can only be accelerated by heavy metal salts in the form of siccatives and by means of increased temperatures.
Complete chemical hardening: Complete hardening is due to a chemical reaction. This is accelerated greatly due to a rise in temperature and airspeed as well as by means of radiation drying. Chemically dried films are insolvent, therefore never chemical on physical!
Thermal drying: Complete hardening is achieved by high temperatures (>100°C), therefore this procedure is not suitable for wood and wooden materials. This involves so-called baked lacquer