Mine was wooden but was decorated with metal (maybe nailheads) and some fake jewels. Since it was sticking out of my carry-on bag, it was very obvious that I had a boomerang with me. I don't think anyone could have missed it, even without the X-ray machine. However, I don't remember whether any of the security screeners commented on the boomerang; I know they didn't ask me about it or examine it in any way. The bigger problem with airport security was that size and weight limits for carry-on are much stricted in Australia than in most of the rest of the world and I did encounter some trouble that I hadn't anticipated on that issue.