The cup is coated with water-based material. In fact, plastic-free cups are produced with the new technique. We use 70% water-based, 30% metallic salt of ethylene-methacrylic as the print coating.
The metal salt of ethylene acid is a low molecular monomer. It is similar to water-based inks, but printing inks are acceptable. Coating of monomer components is also a decomposable option.