Foundation is the material that is inserted into the frame to be used as a starter for the bees to build on. You'll hear a lot of opinions about foundation materials but we feel wax is the natural choice. If you ever hear of a colony not wanting to build on foundation it will be on plastic foundation. Our wax is pure beeswax probably the thickest you'll see anywhere. Plastic foundation is used by a lot of beekeepers so we offer it as well.