Question: what are the most common materials used for barriers?
Answer: Barrier packaging materials: Metals. Metals such as tinplate (tin coated steel) and aluminium are used in can and tray manufacture. ... 
Glass. This was the preferred material for food packaging due to its inertness and non-toxic nature. ... 
Plastic. ... 
Laminates. ... 
Additives and enhanced packaging. ... 
References. ... 
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