Chris, you can certainly split UNI 8/0, I just went to the vise and did it easily. Run your bodkin along a length of thread to break the slight bond (a couple of times if using waxed UNI-Thread), give the bobbin a light ccw spin to remove the twist. Take the point of the bodkin near the hook and you will see that the thread is perfectly flat and starting to separate. Split with the point of your bodkin. Unwaxed UNI 6/0 is a dream to split. Of course UNI-Nylon, 70 or 210 Denier, is even easier as the first two steps aren't needed because it is an untwisted, unbonded, thread.
Ray, see my advice to Chris. You can split any 3/0 thread except perhaps a rope twist, but there is no need (or purpose) in going that large. Cheers, Paul http://www.galesendpress.com -- Paul Marriner Outdoor Writing & Photography. Member OWAA & OWC. Author of Stillwater Fly Fishing: Tools & Tactics (Print [NEW] & CD), Modern Atlantic Salmon Flies, Miramichi River Journal, Ausable River Journal, and Atlantic Salmon.
