Knotty OakBy “knotty oak”, we mean a natural and vibrant variety of oak. Its natural appearance is characteristic of this wood. It also possesses visible knotholes and rifts, which are sealed with black marble filler. “Knotty oak” is an alternative to traditional, homogeneous oak for everyone who likes something particularly authentic. The composition of wood we use demands a trained eye as well as a good feel for its overall appearance; requirements that ZEITRAUM meets thanks to its decades of experience in working with untreated wood.