One of the most popular finishes is water-based polyurethane. Polyurethane mixtures feature high scratch-resistance, adding thick, durable layers to the surface veneer of your planks. Polyurethane finishes are also eco-friendly. They release the least amount of VOCs (volatile organic compounds), which means they produce minimal amounts of pollution and toxins. Water-based finishes go on clear, allowing your wood’s natural burls and coloring to shine through. They also come in various sheens, offering matte and glossy final looks. They dry quickly, which speeds up the refinishing process and puts your floors back in business by the end of the day. However, water-based polyurethane requires multiple coatings—three or four layers—with drying and sanding between each coat.