This looks a little fruity. Perhaps we should take the zorder from the keyword if it has been set, otherwise use the collection's-.1.

The reason this exists, I think, is because despite the zorder, artists are drawn by ```(zorder, type)``` groups meaning that multiple collections will be drawn before multiple patches of the same zorder (I've not explained this very well, so if this is meaningless to you, please probe deeper :smile:).