This tip is from big wall expert Mark Hudon. See more great tips and El Cap route photos at his website, hudonpanos.com
There are lots of different flavors of rope to choose from, but here’s one that should suit just about everybody:
10 mm minimum because you want burley; haul ropes take a LOT of abuse!
60-70 meters long, because you can use the tail of the rope as a lower out line, and 70 meters is long enough for any pitch. A 60 meter rope should work fine for most routes as well.
Static, because hauling on a dynamic rope is not so fun; you have to pull all of the stretch out of the road before you even start to move your haul bag. However, some big wallers like using a dynamic rope for hauling, reasoning that if the lead rope were to be damaged, you could continue on with the haul rope. Like with most things in climbing, this can come down to subjective preferences, so give each one a try on a practice wall and see which method you like.