Just thought I would add my 2cents here.
I just finished wrapping my header and I would like to make a couple of points.
First of all, I had a 50 foot roll 2" wide and I was about 4 inches short at the end. Maybe I could have made the overlaps smaller but I didn't and I didn't want to take it all off and start again. So if you have a 50 foot roll then be aware that you may not have lots of room for error.
Second, definitely wet it. It's so much easier.
And lastly....wear gloves. The fibers in that wrap will itch like hell for many hours and after many hand washes.