History of Invisible Ink and Present Day Use
Invisible ink was first invented in 1775. The main reason why invisible ink was first invented for war purposes, so individuals were able to communicate in private through letters that were written to each other. For example, both the British and Americans would use invisible ink as a form of communication during the revolutionary war (Invisible Ink, n.d.). Another example is during World War one when German spies in the United Kingdom would use invisible ink made by citrus juice to contact Germany. Later on, the British caught on and found eleven German spies who were secretly contacting Germany. While the British were investigating more on the German spies they found lemon, ink nib (the part of a pen that releases the ink onto paper) and pulp (which was used for writing) on the bodies of the German spies (Anna, 2014). In the present day, the most common way you would see invisible ink being used is in amusement parks. Parks such as Disneyland, for example, use invisible ink to stamp an individual’s hands. Once exiting the park, to allow them reenter they will have to use a UV light to check their hand for the invisible ink.
The Science Behind Invisible Ink
Creating invisible ink is not overly complicated, however, there is science behind this phenomenon. According to Wonderopolis (n.d.) there are many ways invisible ink can form. First is through heat activation which is known to be the simplest way. Individuals need organic liquid and once they write their message on a piece of paper the ink becomes invisible after the ink has dried. After that, heat or ultraviolet light is needed to make the message visible to the naked eye. An example of this is cobalt chloride and once the message is heated it will turn blue. The second method is using chemicals. Individuals need to mix two colourless chemicals, once the two colourless chemicals mix the colour will start to appear making the message visible to the reader. This means that the writer writes the message with one chemical, the reader will need to use the second chemical to activate the message. An example of this would be sodium chorine needing silver nitrate to activate the chemicals to reveal the message. However, individuals do not need special chemicals to cause this reaction. In fact, creating invisible ink is extremely easy and could be done with ingredients that you have at home. For example, one way is using lemon, water, paper, cotton swab, and a lightbulb or candle (Rising, 2023).
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The Down Side to The Invention of Invisible Ink
Although invisible ink is fun and practical, like everything else, there is a downside to the invention of invisible ink. Invisible ink can be related to criminals who deal with financial documents, bills, cheques and others (Anamika & Kumar, 2020).
What Makes Invisible Ink Different?
What is fascinating about invisible ink is how print is usually made for everyone and is made permanent. However, invisible ink can fade away through time. Invisible ink still has the same job as any other type of print does, which is to communicate or express oneself, but on a different scale. Invisible ink is made for only a specific amount of people which means it is made to be private, secretive, and not for the public eye. This contradicts most types of print as in most cases, it is made for everyone to see.
My Personal Experience With Invisible Ink
Personally, as a child I would remember getting invisible ink and playing with my friends. I bought an invisible ink pen. The cap of the pen had ultraviolet light attached to the top of the cap and when you remove the cap it would appear as a normal pen, and can write. Looking back, playing with my friends and writing these secret messages could have enhanced my writing skills and my spelling. My friends and I only wanted to communicate through writing secret messages to each other, so this had forced me to write more than I already was in school originally. I think that if nowadays technology was not introduced to children at such a young age, children would still be playing with invisible ink pens and overall would be writing physically. Communication between children has not changed, but the way they are communicating differs from how it was ten to twenty years ago. Maybe children could be using invisible ink to express themselves and communicate to each other instead of texting, for example.
References
Anamika, D., & Kumar, S. (2020). A BRIEF REVIEW ON INVISIBLE INK: IT’S VARIOUS TYPES AND EXAMINATION METHODS. https://jusst.org/wp-content/uploads/2020/10/A-BRIEF-REVIEW-ON-INVISIBLE-INK-ITS-VARIOUS-TYPES-AND-EXAMINATION-METHODS-2.pdf
Anna. (2014, April 27). The messy history of invisible ink. The Pen Company Blog. https://www.thepencompany.com/blog/ink/messy-history-invisible-ink/
Invisible Ink. (n.d.). UM Clements Library. Retrieved November 5, 2023, from https://clements.umich.edu/exhibit/spy-letters-of-the-american-revolution/secret-methods/invisible-ink/).
Invisible ink. (2020, November 5). Wikipedia. https://en.wikipedia.org/wiki/Invisible_ink
n.d. (2020, December 3). Who invented invisible ink?. Grateful American® Foundation. https://gratefulamericanfoundation.org/who-invented-invisible-ink-today/
n.d. (n.d.). How does invisible ink work?. Wonderopolis. https://wonderopolis.org/wonder/How-Does-Invisible-Ink-Work.
Rising, H. (2023, October 23). How to Make an Invisible Ink Message: 6 Simple Ways. WikiHow. https://www.wikihow.com/Make-an-Invisible-Ink-Message.