Originally Posted by waaaasabi

In my experience, the problem with doing it horizontally (even going from top to bottom with overlap ala Kenchan's method) is that if you encounter adverse weather (i.e. a storm or whatever), the tape will loosen up a bit and it'll catch more wind horizontally than vertically (since you're moving forward). Kenchan's method will prevent the tape from mostly flying off, but there will definitely be parts that will lift up/come off and fling about. When I switched to doing it vertically (experimented with starting from the middle, then from the sides), I didn't have a problem with any areas coming off, even in rain. Obviously, the downside to the vertical pattern is that it is more costly, in terms of both time and material.