Beekeepers use wax foundation sheets inside their frames, this helps the bees build the comb within the frames. This prevents crazy comb, which is what beekeepers call the comb that bees build not in the correct location.
A hive with crazy comb is very difficult to inspect, you will also lose valuable resources that the bees have stored in this comb, such as brood and honey.
You will also need to purchase Bee Frames and Wire in order to secure the Wax Foundation within the frames.
Candle makers also purchase Wax Foundation to roll up and make candles from.
The wax foundation comes is different thickness, dependent on your purpose. This foundation is medium brood sized (2 mm). Which is good for most applications.
You will need one Wax Foundation sheet per frame. For people with 1/2 Depth frames you can cut a full sheet in half.
These sheets are designed for non-grooved bottom bars and have the following height:-
Full – 205 mm
3/4 – 145 mm
Here is a video on how to install the wax sheets:-