One of the key advantages of double lined coffee cups is their insulation properties. Made from two layers of glass, these cups effectively trap heat, allowing your coffee to stay hot for longer periods while the outer layer remains cool to the touch. This means that you can enjoy a steaming cup of coffee without the risk of burning your fingers. The thermal insulation also ensures that your cold beverages, like iced coffee or smoothies, maintain a refreshing temperature without condensation forming on the outside. This feature is particularly beneficial during warm summer days or when serving chilled drinks.