Hand-painted oil paintings can last for generations if properly cared for. They should be kept away from direct sunlight, extreme heat, and humidity. Dust should be removed gently with a soft brush or dry cloth. Avoid using water or household cleaners on the surface. If the painting needs repair or cleaning, it is best to consult a professional conservator. Varnishing can also protect the surface, but it should be done only after the paint is completely dry. Proper framing and storage further help preserve the beauty of oil art.