Vufolds high quality unfinished internal bi fold doors can easily be painted, stained or varnished (Polyurethane). We do not recommend using a wax or oil as this can cause various issues with the wood and will invalidate your warranty. Once you have decided what type of finish you prefer you then need to consider the durability and sheen level of the finish. The most popular choices are: Gloss (semi/full) - Is a very durable finish, it also reflects the light when dry resulting in a mid to high sheen. Matt - If you're looking for something more natural, these finishes deliver a smooth subtle look and show little to no sheen when dry as they absorb the light. Satin - Has some of the durability of gloss combined with low to mid sheen levels of matt, it's a great all-rounder.   Vufold recommends the use of Dulux, Sadolin and Sikkens products for our range of Oak veneer internal bi fold doors.