These red wine glasses are exquisitely crafted. This means that each special product is individually mouth blown and hand-finished by skilled artisans. Hand-blown crystal wine glasses are generally lighter, thinner, and more graceful than machine-made ones. The beautiful sound resonates that is like a distant church bell.when you flick or clink a piece of crystal. Tap the piece gently along the rim with your fingernail, if the piece is real crystal, it will ring out with a pleasant tone. But glass emits more of a noise sound