baby ball chair. The Baby Ball Chair is a pint-sized companion to the Ball Chair, from the wild imagination of Finn Stone. Stone, a leading British sculptural artist with an eye for the practical, produced this chair with the idea that it could be used anywhere. Because it is manufactured from polyethylene, it can be used indoors or out all year round. The Baby Ball Chair has the kind of fun and adaptable shape that feels comfortable in any modern environment.