Made from raw New Zealand Pine, these 10 frame Whitehouse Beekeeping Supers are free of chemicals and finishes - simply use outdoor primer and outdoor paint or oil. General rule of thumb is to add new supers when the one below is 80% full / drawn or 8/10 frames. This is obvious when there is white wax constructed on the above combs. Please note, sometimes bees can work up the middle and ignore the outer frames. If you suspect they're not filling up the outer frames, then you need to place the unfilled frames in between the full frames.