Invisible ink revealed by UV light for fountain pen — ARCANE
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In the box
- 1 18 ml glass bottle of UV invisible ink
- 1 pocket UV light (Ink + UV light only version)
All you need to know
Revealed under UV 18 ml ARCANE invisible ink writes messages that no one sees… until they are illuminated. Transparent on paper, it reveals itself in luminous blue under UV light, like a secret that lights up in the dark. Presented in an 18 ml glass bottle with a black cap, this carbon-free fluorescent ink is designed for the fountain pen and the glass dip pen, with which it flows smoothly. It comes in two versions: ink only, for those who already have an ultraviolet lamp, and the ink with a small silver metal UV pocket lamp, to reveal messages wherever you are. Secret letters, treasure map, mystery game, hidden signature on a notebook, or a drawing that only appears when night falls: ARCANE adds a touch of mystery to stationery and provides a highly visual demonstration of fluorescence.
Fluorescence, or the art of making the invisible visible
A fluorescent ink contains molecules that absorb ultraviolet rays, invisible to the human eye, and immediately re-emit them in the form of visible light. Under normal lighting, the ink remains almost transparent; under a UV lamp, it glows a bright blue. As soon as the lamp is turned off, the glow disappears: this is what distinguishes fluorescence from phosphorescence.
The principle is old: it can be found in the security markings on banknotes or the entry stamps at nightclubs. With ARCANE, it becomes a writing game and a hands-on physics experience with light that you can do at home.
Why you will love it
The ARCANE spirit
What is written for a single glance
An arcane is a secret, knowledge reserved for a few initiates. Secret messages have always fascinated us: lemon juice revealed by flame, encrypted codes, letters hidden in a false bottom. ARCANE offers a modern and luminous version.
Dip your pen, write a few words that disappear as they dry, then hand over the letter. The recipient sees only a blank page… until the UV beam brings forth text in an electric blue.
It is a game for puzzle lovers, a ritual for fountain pen enthusiasts, and a little physics lesson about this part of light that our eyes cannot see.
Write a secret message in 4 steps
Which version to choose
| Criterion | Ink only | Ink + UV lamp |
|---|---|---|
| Invisible ink | 18 ml | 18 ml |
| UV pocket lamp | No | Yes |
| Ready to use | With your own UV lamp | Yes, upon receipt |
| Ideal for | Refills, already equipped enthusiasts | First purchase, gift |
Good to know: the result depends heavily on the paper. Many printer papers are “blued,” meaning they are treated to look whiter: they glow themselves under UV and reduce contrast. Choose natural, cream, or light kraft paper for a more legible message. The UV lamp also makes certain minerals glow, such as the LUCIOLE yooperlite.
Tip: if you use a fountain pen, preferably reserve it for this ink and rinse it with clear water before returning to a regular ink. With a glass dip pen, simply dip it in a glass of water and wipe it between inks.
Technical specifications
| Type | Fluorescent invisible ink |
| Volume | 18 ml |
| Color in daylight | Transparent |
| Color under UV | Luminous blue |
| Composition | Carbon-free ink |
| Compatible instruments | Fountain pen, glass dip pen, dip pen holder |
| Bottle | Glass, black screw cap |
| Versions | Ink only, ink + UV lamp |
| Lamp (version with lamp) | Silver metal UV pocket lamp, attachment ring |
| Revelation | Ultraviolet light, in a dark room |
| Recommended support | Matte unlined paper |
Precautions for use: never point the UV lamp beam at your eyes, nor at the eyes of another person or an animal. The ink must not be ingested or applied to the skin; keep the bottle and lamp out of reach of young children and close the bottle tightly after use. The ink can stain textiles: protect the table and your clothes.
A gift full of mystery
The ink + UV lamp version is an original gift ready to use: for a fountain pen enthusiast, a puzzle and escape game lover, a teenager who loves secret codes, or a couple who likes leaving sweet notes for each other. It is suitable for a birthday as well as Christmas.
Tip: give it with a card written in invisible ink, and slip the lamp into the package so the recipient can discover the message themselves. To extend the experience, add a Lab object centered around light.
To pair with
Frequently asked questions
How does UV invisible ink work?
ARCANE is a fluorescent ink: it contains compounds that absorb ultraviolet light, invisible to us, and re-emit it in the form of visible blue light. In daylight, the dry text is almost invisible on the paper. Under a UV lamp, ideally in a dark room, it immediately lights up in blue. As soon as the lamp is turned off, the message disappears again: it can be revealed as many times as you wish. The darker the room, the more striking the contrast.
What pen can it be used with?
The ink is designed for fountain pens and glass dip pens, and it can also be used with a classic dip pen holder or a fine brush. It is a carbon-free ink, fluid, designed for these instruments. With a fountain pen, we recommend rinsing it thoroughly before and after use, and ideally reserving it for this ink. With a glass dip pen, simply dip it in clear water and wipe it to change ink. However, it is not intended for ballpoint pens or felt-tip pens.
What does the version with the UV lamp contain?
The “Ink + UV lamp” version brings together the 18 ml ink bottle and a small silver metal UV pocket lamp, equipped with a ring to attach it to a keychain. It allows you to reveal your messages upon receipt, without additional equipment. The “Ink only” version contains only the bottle: it is intended for those who already have an ultraviolet lamp or want an ink refill. The bottle and lamp fit in a pouch, to reveal a message anywhere.
Is the message really invisible?
Once dry, the ink is very discreet in daylight, but a slight reflection may remain visible depending on the angle, the paper, and the amount of ink deposited. For the most invisible message possible, write without loading the pen too heavily, on matte paper, and let it dry thoroughly. Avoid glossy papers, on which the ink dries poorly, and very white “blued” papers, which glow themselves under UV and reduce the contrast of the revealed text.
How long does the message remain legible?
The text remains on the paper and can be revealed with each pass of the UV lamp. Like all fluorescent inks, it may lose its brilliance if exposed to direct sunlight for a long time. To preserve a letter or secret page, store it away from light, in a notebook, an envelope, or a drawer. The bottle is best kept tightly closed, at room temperature and away from light. Properly stored, a secret letter can thus be reread for a long time, with each pass of the lamp.
What ideas are there for using invisible ink?
The uses are numerous: secret letters and sweet notes, a birthday card with a double reading, clues for a treasure hunt or a home escape game, a hidden signature on a notebook or drawing, discreet marking of your books and objects, a drawing that only reveals itself when night falls. In class or with family, it is also a playful way to explain fluorescence and the existence of a light that our eyes do not perceive. An 18 ml bottle allows you to write many pages.
Is it a good gift idea?
Yes, especially in its version with a UV lamp, ready to use. It is an original gift for a calligraphy or fountain pen enthusiast, a puzzle lover, a curious teenager, or a close couple. It is suitable for a birthday or Christmas, and can accompany a notebook or a glass dip pen. For a successful surprise, write the greeting card itself in invisible ink and let the recipient reveal it. The small glass bottle with the black cap also makes a pretty object on a desk.
