I'm trying to create something looking like a baobab tree, and I'm right out of ideas for a fish safe form to keep the moss on that won't show up too much. Getting all the tiny branches attached in to a thick piece of driftwood is out since they'd be so thin that they'd snap easily. I also can't imagine trying to hide the joins of the branches to the wood gracefully. So, does anyone have any ideas for materials that I could make a fairly precision structure out of for the moss to grow on?