Japanese titanium is a very strong and lightweight material that is often used in eyeglass frames. It is durable and corrosion resistant, making it a good choice for glasses you will wear every day. Acetate, a type of plastic, is also a popular material for eyeglass frames because it is lightweight and flexible, making it comfortable to wear. It is also hypoallergenic, so it is suitable for people with sensitive skin. The German brand Coblens is known for producing quality glasses, so glasses made from these materials of this brand are of high quality and durability.