Tapered leaders are a great way to make your main line more streamline. You tie the thinnest part to your main line, which will reduce (not stop) weed at your top ring, and the thickest end to your weight (or trace). Tapered leaders are normally around 13m long and taper from 16lb b/s at the thinnest end up to 65lb b/s at the other end. So you have a leader sufficient for breakaway leads of up to 170g.