Best invisible ink pen

Supplies

The classic “lemon juice as invisible ink” method of writing secret messages works with nearly any fluid with high acidity. Exposing these substances to heat causes them to oxidize and turn brown.

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Which invisible ink pens are best?

Spies and conspirators have used invisible inks for millennia to send messages. In the modern age, invisible ink pens are an excellent way for grown-ups to discreetly mark items in their workplace and a great toy for kids who want to play games of subterfuge.

The SCStyle Invisible Ink Pen set is a perfect gift for large groups of children. Other invisible ink pen products may have designs, ultraviolet lights or ink hues that better fit the specific needs of certain buyers.

What to know before you buy an invisible ink pen

How ultraviolet invisible ink pens work

Ultraviolet invisible ink pens and markers contain a special type of ink made from naturally fluorescent chemicals or organic compounds. When you shine a UV light down on a message or drawing made with invisible ink, the electrons within the ink’s fluorescent molecules are excited, briefly shifting to a higher-energy orbit around their nuclei. When those electrons shift back to their normal orbit, the absorbed energy is expelled in the form of visible light.

Accessories that go well with invisible ink pens

If you’re planning on giving friends or family members invisible ink pens as gifts, it’s also good to give them something they can write on. Small notebooks and journals pair nicely with invisible ink pens, letting people fill page after page with secret messages and doodles. Sturdy ultraviolet flashlights are another good accessory to purchase alongside invisible ink pens if the UV lights packaged with the pens aren’t up to snuff.

How to make your own invisible inks

You can use many naturally occurring substances to make your own invisible ink, several of which you can find in your own kitchen pantry. Lemon juice, baking soda, white wine and soapy water can all be used to create invisible ink that’s permanently revealed through exposure to heat. Vinegar and ammonia are two transparent substances that become visible when exposed to red cabbage water. Diluted laundry detergent, spit and Vitamin B-12 dissolved in vinegar can be used to make invisible ink revealed by the shine of ultraviolet light.

What to look for in a quality invisible ink pen

Ink that’s washable and nontoxic

Many invisible ink pen products are marketed towards children as cool accessories to use at parties, in schools and during make-believe games. With this in mind, always make sure the pens you purchase use invisible ink that’s nontoxic and easy to wash off of clothes, walls, skin and other surfaces young children like to draw on.

Batteries that can be easily replaced

These days, most invisible ink pen products come with small ultraviolet lights built into their caps, penlights powered by small, button-shaped battery cells. If you’re looking to buy a UV invisible ink pen that you can use for a long time, try looking for a model powered by button cell batteries that are easy to find in stores or order online.

Ink cartridges that won’t run out too quickly

If you’re going to use invisible ink pens regularly, it’s generally good to search for pens with a high ink capacity or the ability to be refilled. Alternatively, purchase a large package of cheap invisible ink pens in bulk, so you don’t need to rely on individual pens.

How much you can expect to spend on invisible ink pens

Large packages of invisible ink pens cost around $20, while smaller packages cost $10 or less.

Invisible ink pen FAQ

When was invisible ink first used to write secret messages?

A. References to invisible ink appear in Greek military treatises and historical accounts dating back to the 4th century BCE. Many early invisible ink recipes involve mixing two chemicals to reveal a message. For example, pouring ferrous sulfate over an invisible message written with gallnut ink.

Do contemporary intelligence agencies use UV-sensitive invisible ink?

A. Many modern-day spies and intelligence experts frown on the use of invisible ink messages that you can reveal through ultraviolet light, in no small part because UV flashlights are so ubiquitous in this modern age. The ideal invisible ink for secret messages, some say, should be completely odorless and only revealed when exposed to very, very specific conditions.

What are the best invisible ink pens to buy?

Top invisible ink pens

SCStyle Invisible Ink Pen

SCStyle Invisible Ink Pen

What you need to know: This pack of 28 invisible ink pens is a great group gift for kids in school or at parties.

What you’ll love: Each of the 28 invisible ink pens in this pack comes with ultraviolet lights built into their caps. The permanent, washable invisible ink within the pens vanishes shortly after being used to write words and becomes visible again when exposed to UV light.

What you should consider: The casings of these invisible ink pens come in different colors, but the color of the ink itself is uniform.

Where to buy: Sold by Amazon

Top invisible ink pens for the money

FLYOME 4 Pack Invisible Ink Pens

FLYOME 4 Pack Invisible Ink Pens

What you need to know: This small pack of invisible ink pens is a fun, affordable gift for parties and holiday events, particularly with kids who like to play spy games or detective games.

What you’ll love: The UV lights in the covers for these invisible ink pens are powered by three LR44 button batteries. The UV-sensitive ink in each pen can write messages and sketch images on both paper and skin.

What you should consider: According to some customers, the battery power and ink in each pen quickly run out after regular use.

Where to buy: Sold by Amazon

Worth checking out

VOVRU Invisible Ink Pen

VOVRU Invisible Ink Pen

What you need to know: The 24 pens in this invisible ink pen pack each come in their own invisible package, making them a great gift to hand out to large groups of kids.

What you’ll love: The packaging of these UV-sensitive invisible ink pens is marketed towards kids who want to play “detective” and “spy” games with each other through the exchange of hidden messages.

What you should consider: The batteries installed in the UV light covers of these pens are product-specific, and it’s hard to find replacements for this product.

Where to buy: Sold by Amazon

 

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Coleman Gailloreto writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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