Otti coverings are hand manufactured, individually, with moulding process, for this reason there may be differences of shades and size in mm between the tiles. This is not an error, the binding net will be rustic and unrepeatably unique, just like natural stone, in case of which there aren’t two identical pieces either. The concrete in this case means a quartz product of high hardness which has better properties than most natural stones, regarding its resistance to abrasion, possibility of cleaning and installing. In case of coloured tiles, the wear layer is coloured in several centimetres thick in its material. This provides the extreme durability.