Liner "material" usually refers to the film used. The film used merely depends on the sensitivity of the packaged liquids. Most products(oils, liquid egg, sauces) can be packaged using a VLDPE film. Others however have to be protected against oxygen(apple concentrate changes in color) and are mostly packaged using EVOH or PET-MET film material. Also other products, such as water requires specific foil to prevent the water from getting a "plastic taste". Qbig advices you in choosing the correct film for your requirements.
