We just received a shipment of foundation and thought it would make a great post here.
Cell size refers to the size of the hexagons imprinted on the wax. Small cells yield smaller bees and potentially fewer varroa mites. Medium cells are standard in the beekeeping industry. Drone cells are the largest and will stimulate more drone bees in the hive.
Midrib thickness refers to how thick the foundation is, if you look at it from the side. The midrib is the wax that supports the cells, which poke out from it on either side. The thicker the midrib, the sturdier the foundation. Medium brood foundation is foundation with a medium-thick midrib. Thin surplus foundation is often used for producing honeycomb. Plastic foundation is all medium brood thickness.
Frame size refers to whether the frame is shallow, medium, or deep.
Above is a frame with medium cell size, deep frame size plastic foundation. It is coated with a thin layer of beeswax. We use Permadent foundation. Permadent is a brand name similar to Rite-Cell by Mann Lake and Plasticell by Dadant. This is the foundation we use the most.
Middle: Medium cell, Medium midrib, Deep frame size.
Right: Medium cell, Thin surplus midrib, Medium frame size.
We are experimenting with wax foundation in the Barn Hive. We use it to produce comb honey in deep middle bar frames. The medium midrib foundation holds up well both in the hive and in the extractor.
We avoid Duragilt foundation. It has a beeswax cells added to a plastic core. Unfortunately, the beeswax cells peel off and leave blank, slick plastic behind. The bees avoid stripped areas won't build comb there.
We haven't experimented with wired wax foundation and would really prefer not to wire our frames, as it is very labor-intensive. This is why we go with plastic Permadent foundation most often.