(KERO) — People have seen it in spy movies, secret messages written through invisible ink. As it turns out, the average person may have all the ingredients needed to make their own invisible ink right ...

Invisible inks based on “smart” fluorescent materials have been shining brightly (if only you could see them) in the data-encryption/decryption arena lately ...

What looks like magic is often just a rule of physics or chemistry doing its job. Invisible ink turning brown, colours swirling on milk, water climbing uphill — it all feels like sorcery until you ...

So you want to open sealed envelopes without getting caught? Here’s the secret, according to one of the six oldest classified documents in possession of the Central Intelligence Agency: “Mix 5 drams ...