Graphite or pen and ink? New dog portrait

I'm working on a new dog portrait. This one is of a beautiful, fluffy dog with long, white hair. I've done a rough sketch in graphite, but am unsure if the final will be in graphite or pen and ink. I am planning to do some work in both mediums to see what looks best. Because the dog is all white, I don't want to overwork it, either way. So, this will be an interesting challenge. I'm looking forward to seeing how it progresses.