This spell of invisibility requires some experience and mental strength. You memorize a poem, and after a long period of time your physical body becomes blurred when you repeat it for a while.
No, you do not disappear in front of everyone. But if someone is thinking of you, you can walk around and go unnoticed, like a chameleon, which merges into the surroundings.
This is the poem:
A piece of fog, a dragon’s eye, a pattern of the chameleon.
I reflect. Where now light is shed, There is no me there.