What Wire Covering?

If your wiring is really done, I would tape it up. Near the end of the loom, just put a heat shrinkwrap over the tape to prevent it from coming loose.

But if it's like mine, where you'll be adding or rerouting a few wires once in a while (Megasquirt), it's way easier to be able to add/remove wires from the loom easily, so I used a split/slit harness for the time being, like this;
Slit Harness Wrap | Wire Bundle Wrap - CableOrganizer.com

Although, on a daily driven car, I don't really like it when the wire harness cover is 'open'. Dirt and grime will find its way inside and make everything appear black over time.