There was a time when glass was a craft. But in recent years it has become something more: an established art form, and an attractive—and affordable—investment.

"Art glass is a great way to begin collecting art because there is so much available at so many price points," says Carina Villinger, head of 20th century decorative art and design at Christie's.

Since the launch of the Studio Glass movement in the 1960s, glass has slowly crossed the species barrier from craft to fine art. Today, examples of glass art include bright colors and arresting shapes, works that resemble paintings in glass, and objects both strange and familiar encased in glass.