Traditional surface treatment of specially pressure-impregnated wood has for decades been dominated by drying oils, such as linseed oil and alkyd oils. These dry out by oxidation with the oxygen in the air. This normally entails a long drying time and thus a risk that the surface may absorb dirt and give rise to growth.

To increase the penetration of oils, organic solvents are most often used as promoters. In recent years, bleaching methods for wooden surfaces have also been introduced. These are normally based on water glasses with high alkalinity and corrosivity. The bleaching method is a multi-step treatment where the wooden surface should finally be surface-sealed to be functional. Repeated treatments of the bleaching method are required to achieve the visual effect. Bleaching methods are difficult to surface treat with the choice of another future surface protection.

Surface treatment of bleaching methods, which are highly alkaline, should for this reason take place relatively frequently to prevent, for example, growth. The surface treatment gives low wear resistance.