The top and bottom layers of the PE liners are composed of solid low-density polyethylene (LDPE) with a low-density foam core in the middle, creating a liner that is compatible with many products. These liners provide excellent chemical resistance to acids, alkalis, solvents, alcohols, oils, household cosmetics, and aqueous products. They also offer low moisture transmission rates, odor resistance, and do not alter product taste.

Many PE lined plastic caps are composed of polypropylene; a stable, and chemically resistant plastic that is easy to mold. Polypropylene plastic has high impact strength and a naturally smooth, slightly shiny surface without added deco applications.