Oil-based varnishes are protective finishes made from a combination of oils, resins, and solvents. They are commonly used on wood surfaces to enhance appearance and durability. These varnishes penetrate the wood, providing a rich, warm finish while also protecting against moisture and wear. One of the key benefits of oil-based varnishes is their ability to create a hard, glossy surface that resists scratches and stains. However, they typically take longer to dry compared to water-based varnishes, and their strong odor can be a consideration during application. Proper ventilation is recommended when using them.