Flashing (weatherproofing) bark was occasionally used as a flashing material. Most flashing materials today are metal, plastic, rubber, or impregnated paper. Metal flashing materials include lead, aluminium, copper, stainless steel, zinc alloy, other architectural metals or a metal with a coating such as galvanized steel, lead-coated copper, anodized aluminum, terne-coated copper, galvalume (aluminum-zinc alloy coated sheet steel), and metals similar to stone-coated metal roofing. Metal flashing should be provided with expansion joints on long runs to prevent deformation of the metal sheets due to expansion and contraction, and should not stain or be stained by adjacent materials or react chemically with them.
Coated paper to make paper cups and photographic paper. Biopolymer coatings are available as more sustainable alternatives to common petrochemical coatings like LDPE (see plastic-coated paper) or mylar. Printed papers commonly have a top coat of a protective polymer to seal the print, provide scuff resistance, and sometimes gloss. Some coatings are processed by UV curing for stability. A release liner is a paper (or film) sheet used to prevent a sticky surface from adhering. It is coated on one or both sides with a release agent. Heat printed papers such as receipts are often coated with estrogenic and carcinogenic poisons, such