What is the best rope for a rope swing that ensures safety and durability for outdoor use?

The best rope for a rope swing that ensures safety and durability for outdoor use is typically a high-quality marine-grade rope, such as polypropylene or nylon. These ropes are strong, weather-resistant, and have a high weight capacity, making them ideal for supporting the weight of a person on a rope swing. It is important to choose a rope that is thick enough to handle the weight and force of swinging, and to regularly inspect and maintain the rope to ensure safety.