Well, as you may have guessed by now, the method of invisibility I am about to teach you is based on psychological effects. It's not hypnosis, and it will work on over 99.9% of the people you will encounter on your invisible travels, but it is not 100% foolproof (and I have yet to see proof of any method that is). It also requires a lot of mental effort to sustain the invisibility, so plenty of practise is required. To begin with, you may experience only moments of partial transparency, but with enough training you should be able to go for over an hour in full invisibility. My personal record is over 80 minutes of sustained transparency!