Butterfly Knives The American butterfly knife is based on the traditional Pilipino Balisong. The basic idea of butterfly knives is that the knife has two handles that rotate around the tang so that, when the knife is closed the blade is concealed within the handle, but it can be quickly and easily deployed by a skilled user. The first butterfly knives in America were brought back from the Philippines by soldiers after World War 2. There was a brisk business in importing handmade butterfly knives from the Philippines until its import was banned in the mid 1980’s. There are still vintage high quality knives commercially available, but there are also now many cheap butterfly knives of reasonable quality being imported from China and other Asian manufacturers.