Every other plane is identical. Construct the layers shown using 2-inch spheres and pipe cleaner pieces as above. Place the first layer flat on the desk. Place the second layer on it so that the spheres rest in the spaces between the corner spheres of the first layer. Place the third layer directly over the first layer.
Every third layer is identical.
Set aside the closest packing model just prepared from planes of spheres. Place this face-centered packing model alongside the hexagonal closest packing. Remove the top layer of the face-centered packing model. Note that these models, built by different schemes, are really identical in terms of the shown internal arrangement of spheres. Place one square layer on the surface.