In China, the traditional bow saw has been in use for more than 2000 years. It cuts a thin kerf and does so fast. A bow saw can be used for many aspects of joinery for instance cutting tenons and dovetails. He makes it using construction timber and an inexpensive blade. The wood he uses is spruce. When you buy the blade make sure it is one of the sort that you can sharpen. In the video he talks about the cut list. That confused people so he deleted it.