Thermally modified timber (TMT) is wood treated at high temperatures, and this process changes its characteristics in such a way that it is sometimes described as ”domestic tropical timber“. In the controlled atmosphere of a special chamber the timber is treated at temperatures of up to 250° C. Due to the heat and humidity, the sugar compounds in the wood (hemicellulose) are reduced, the sugar is caramelised and changes the composition of the cell wall. The timber is thereby endowed with new characteristics, such as reduced water absorption, longer durability, resistance against fungi and insects; moreover, its colouring becomes darker and more refined. All changes in colour take place consistently across the entire cross-section, i.e. also on the inside of the timber. The colouring can be varied depending on the length of the treatment and the characteristics of the raw material. This process is purely thermal and does not involve the use of chemical substances.