There is a knife being sold on a well known auction website currently, and I've gotten a few emails asking about it's authenticity. Based on the pictures posted in the auction, I can't for certain say it is a Lum custom. Which begs the question: how can you tell? For starters, Bob always signed his work. Prior to the famous "Chop" logo, he would stamp the letters LUM on the ricasso of the blade. See the picture of the two ivory tantos by Jim Cooper for an example. There are exceptions. I have one knife he has authenticated to be his where he signed the knife with his Chinese Lum character on the brass pin, but this was one of his earliest work. Then there is his hand-rubbed satin finish. One of his signatures. It's very easy to spot the Lum finish once you've seen it before. His grind lines. As mentioned before, Bob is considered by many knifemakers to be one of the best grinders in the business. His grind lines are always clean and symmetrical. The best w...