During the growth phase of the tree the purpose of medullary ray is to transport nutrition between the core of the trunk and the outer parts. The medullary rays are almost an unnoticeable colour in some other wood species. In the Oak trunk crosscut they are quite clearly visible as pale stripes reaching to the core of the wood. Some of the medullary rays remain "inside" the wood matter. Partly for this reason there can be pale so called "medullary ray mirrors or stripes" in all parts of the trunk which lend oak its uniquely interesting appearance.
Regardless of the top layer selection, the medullary rays are a rather visible part of Oak hardwood floors. Especially in the more even selections like Select and Nature they stand out more than in the more colourful selections due to the cutting direction and more even appearance. In all of our Oak products, the medullary rays are an important part of the wood's natural colour variation and characteristic and their occurrence has not been restricted in any way.