Are you like, those old multi colour swirly rubber balls we used to get out of 20p machines as kids? Those were ill!
Your username vintage balls reminded me of those little rubber balls we used to get at kids, I don’t see them any more (maybe they’re seen as too much of a choking hazard now?), so they feel kinda “vintage” to me now haha.
Those things could really bounce! I liked the semi translucent ones with the rainbow swirl patterns.