invisible inkAn ink, used for secret communication, that is colorless when written but that can be developed by heat or chemical reaction. For example, potassium hexacyanoferrate (II) ink can be developed by an iron (III) salt, giving Prussian blue. Fluorecent inks fluoresce in ultraviolet light. Related category• INORGANIC CHEMISTRYAlso on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |