All this talk of plastic and ceramic knives, finding ways to fool the TSA, cracks me up.

Get caught by the TSA on a random search, or because you forgot to take your bottle of shampoo out of your bag, and have them find a plastic knife, implying that you were INTENTIONALLY trying to sneak a weapon onto a plane, and see how fast you end up in a federal PMITA prison.

Give up the knife when you fly, mail it to yourself, or put a cheap one in your carry on. Don't be an idiot just for the sake of feeling "protected" for the couple of hours you'll spend in airports or planes, and end up in a lot worse situation than you bargained for.