Living Ink Pen

During the development of algae based ink Fulbright discovered that this ink changed from one day to the next. This resulted in a Living Ink pen which they intend to bring to market mid 2016 with the help of Kickstarter. The pen appears to be a ´normal´ pen, but the text or drawing only appear when they are exposed to sunlight (due to the fact that algae cells multiply rapidly). The effect is fun and offers numerous possibilities, such as extra messages or drawings appearing on greeting cards.
The Living Ink pen will be brought to market mid 2016, in combination with special paper and a glass framce.
Source: Drupa