Phosphorescent inks are invisible under the regular light but when in the dark they reflect a greenish, bluish or yellowish colour, depending on the pigments
. These types of inks may be used for labels of promotional products, drinks and other products available in night environments. Furthermore they are also interesting for product related with children due to their particular and bright properties.
Finally, these types of inks may also be used as a safety application in products that require an automatic and fast authentication such as to verify stamps or medicine boxes.