In contrast to dry food products, the packaging of frozen products can be exposed to moist environments, which can adversely affect the product shelf-life and the shape of the package. To prevent moisture from entering cardboard packages, types of cardboard coatings are sometimes used.  For increasing package rigidity, higher-density cardboards can be used.  Reducing the impact of moisture from the outside of the cardboard, it’s a common practice to cover packages with a layer of UV varnish, thereby creating an additional protective layer.