Brushing usually takes place as part of the manufacturing process, the surface of the planks are roller brushed to remove some of the softer growth rings from the grain. Depending on the level of brushing, this gives a textured surface that gently highlights the natural grain structure.
Distressing is typically achieved by hand or by tumbling the planks in large tanks, giving a used and random appearance. Another distressing method includes machines that scrape and punch the planks as they go through a conveyor belt system although this method will usually show a repeating pattern of distresses which may look unnatural.
Ammonia fuming is a traditional process for darkening and enriching the colour of oak by oxidation. The physical change in appearance is subject to the tannin and other natural content held within the structure of the timber and its interaction with the treatment. It forms an envelope around the surface of the board and depth of penetration will vary subject to the timber structure and exposure, however the outward appearance of the edges could suggest the boards are treated to the core.
Band-sawing usually takes place as part of the manufacturing process, the surface of the planks are notched to create a rough and uneven surface, mimicking the traditional hand-saws used in the pre mechanical era. Machining impressions going across the board will be visible in all areas.
Before modern machinery has taken over, floors were hand scraped on-site to make sure they were flat and smooth. In practice although this method removed the rough grain, it left the floor feel somewhat wavy and uneven. Nowadays the hand-scraping effect is created with special machines.
In thermo-treating, the boards are heated to a high temperature which causes the colour to darken. This method of darkening wood is environmentally friendly as there are no chemicals used during this process, simply heat and steam. The process brings out and accentuates the best grain characteristics of the flooring, and unlike a stain, thermo-treatment changes the colour, creating a deep rich hue running through the entire core of the wood.