I spent two weeks last February in a rented studio outside Toledo, Ohio, learning to make cat's-eye marbles by hand. The instructor, a retired Clearcraft Glass employee named June, kept jars sorted by vane color: aqua, grass green, amber, and a deep red-orange she called "sunset." The vane isn't painted on. It's a ribbon of colored glass embedded while the sphere is still spinning on the marver.
What the Vane Knows
The thing nobody tells you about cat's-eye marbles is how much the effect depends on what sits behind them. Set one on white paper and the colors flatten. Place it on dark velvet and the sphere comes alive: light passes through, bounces off the surface beneath, and returns changed. The vane appears to float in its own small atmosphere.
Glass remembers the last temperature it felt. Every marble keeps a trace of the furnace it came from.
— June Hargrove, glassworker, 1987