Thinking of buying a ring sling - does it matter if the ring is aluminum or plastic?

As long as the product has been stress-tested by the company and there are no noticeable defects on the ring sling, feel free to use it. Nylon rings are made of fully moulded resin and have no weak stress points which can cause them to break. Aluminum rings are also equally durable and strong. The difference is in the weight. Do cover the rings with a sock before washing your ring sling to protect it. http://www.babyslingsandcarriers.com/faqs_babyslings#FAQ005