Bag for use as e.g. food packaging, consists of paper or paperboard, in which printing ink is applied on flat area of the bag for imprinting of prize information, where printing ink consists of safety color

摘要

The bag (1) consists of a paper or paperboard, in which a printing ink is applied on a flat area of the bag for imprinting of prize information (2), where the printing ink consists of a safety color. The safety color is invisible and becomes visible only after a mechanical treatment with a piece of metal e.g. coin, where a coin-color can also be used as the safety color.