Application of coatings by spraying is used in order to protect surfaces against humidity and chemicals. All products should be thoroughly mixed by stirring before application. To facilitate spraying it may be necessary to add additional recommended thinners to the base product up to the level of approximately 20%.

Heating the objects to be sprayed to 50 - 60°C can be favourable when manufacturing techniques require a more rapid cure. If necessary, a second layer of varnish could then be applied after only 10 - 20 minutes. Products typically used for spraying are designed to be air-drying and as such product containers should remain closed and sealed before and after use to prevent evaporation of the solvents and undesired reactions owing to oxidative curing. Some finishing varnishes are delivered in spray cans ready to use.