If you are referring to the Oil/Varnish finish, I have been teaching that for about 25 years. I start with equal parts of BLO or tung oil, any oil based varnish or poly varnish and mineral spirits. This gives a nice looking, warm glow sheen to dark woods like walnut and cherry. It mimics an oil time, multiple application "oil finish". Adding more varnish makes is look more like a film finish. I recommend the finisher try different ratios depending on the "look" wanted. There's not ultimate answer and there's no ultimate finish. Instead, there are multiple finishes that accomplish certain looks and levels of protection.