Harry’s cloak is a Remarkable bit of magic, but real invisibility is not too far off.
On the other hand, the first rule of invisibility is to keep your distance, so maybe being too far off is a good thing.
Mechanical or electronic invisibility is achievable, but biological invisibility will be a challenge. At least the clues are all there. (See squid and octopus, also firefly.)
That’s just it, Bob. According to the gentleman in the clip on camouflage, invisibility clothing isn’t that far away. He’s the guy who designed the digital camo that the military uses, and it’s not just OUR military — it’s military all over the world. When asked point-blank about invisible clothing, his eyes shifted just a bit when he answered.
What thief wouldn’t want that in his arsenal?