Rattan, while not naturally 100% waterproof, can be made more resistant to water and weather-related damage with proper care and treatment. To increase its lifespan and protect it from wear, you can apply waterproof protective coatings, varnishes, or natural oils that create a protective barrier. On the other hand, synthetic rattan offers a significant advantage it is designed to be highly water-resistant and weatherproof, making it a more durable option for outdoor use. By taking these precautions, you can ensure your rattan furniture remains in great condition for years to come.