The square douglas fir slats in the VILLA product line are crafted with an all natural tung oil finish, using pure food-grade limonene (citrus peel oil) as a solvent. Our tung oil finish looks stunning while providing unmatched environmental protection to the wood surface. Our tung oil finish can be periodically refreshed, such as annually or biannually, to maintain its luxurious finish that is smooth and agreeable to the touch.