If you have a Challenger Bread Pan, the domed cast iron lid is perfect for covering the pan while it rises. Be careful when picking it up after the long 8-12 hour rise — if your dough is particularly active, it might be touching the bottom of the lid. If you don't have a bread pan like that, use plastic bowl covers to cover the focaccia during the two short initial resting periods, then use saran wrap to cover the pan itself. You want to avoid letting the plastic wrap touch the surface of the dough as it rises. It's delicate and you don't want the plastic wrap to tear the dough when you pull it up. If your pan is shallow and the plastic wrap will touch the surface, spray the plastic with non-stick spray or add an extra drizzle of oil to the top of the dough to prevent sticking.