UselessFinds
The Invisible Ink Pen With a UV Light in the Cap

writes nothing you can read

Novelty Stationery

The Invisible Ink Pen With a UV Light in the Cap

Write in ink nobody can see, then reveal it with the ultraviolet light built into the pen. Peak nine-year-old spy energy, for pocket change.

Buy this nonsense$1.59(sponsored link, opens in a new tab)
  • invisible ink
  • spy gadget
  • novelty pen
  • kids gift
  • stationery
  • party bag

What Is This Thing?

A ballpoint pen loaded with ink that is invisible under ordinary light, with a small ultraviolet LED built into the opposite end. Write your message, hand the paper over, and the recipient reveals it by shining the pen's own light across the page.

The whole apparatus — writing and decoding — is one object you can put in a pocket.

Why You Don't Need It

Every message you actually need to send is either fine in ordinary ink, or should not be committed to paper at all. The security model here is "hope nobody else owns a UV light," and UV lights cost about a dollar.

Why You'll Buy It Anyway

Because for roughly the price of a coffee you get to be a spy for about four days, and those four days are genuinely fun.

There is also a legitimate use hiding inside the novelty: marking property with your name or postcode in ink that does not deface the object. That is the excuse you will give when someone asks why you own this, and it is not entirely a lie.

The Invisible Ink Pen With a UV Light in the Cap — photograph 2
The Invisible Ink Pen With a UV Light in the Cap — photograph 3

Who It's Actually For

Children, unambiguously. This is a party bag item, a stocking filler, a birthday gift for a kid who is currently deep in a spy phase. The ratings on these are driven by parents.

Also useful for anyone who wants to mark equipment, library books, or gear discreetly — a real if unglamorous use for the same technology.

before you click buy

Invisible ink does not develop equally well on every paper. Glossy and coated stock tends to disappoint; ordinary matte paper works best.

The UV LED is small and battery-powered, and on pens at this price the battery is the first part to go. Check whether the listing includes replacements. Bear in mind too that ultraviolet light should not be shone into anyone's eyes, which is worth mentioning out loud if the intended user is eight.

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