Oregon White Oak bark is used in many applications. The larger pieces are often used in floral and design projects. Oak bark has a high tannin content. In fact, the word Tannin comes from an old German word, tanna, for oak. This high tannin content provides an anti-fungal and anti-bacterial defense for the tree. These same tannins are used by natural healers to provide help to their patients. Oak tannins are also used in tanning leather, clarifying wines, precipitating proteins in beer production, and as an astringent in medicine. They are even used to provide base notes in certain perfumes. The list seems endless. We know we just love looking at oak bark.