I'm currently playing with diamagnetic pyrolytic graphite and I have created a small portion of a track similar to this video I want to create a circular track for it travel on, but as rare earth magnets are getting expensive I'm going to use thinner magnets that consequently have a weaker magnetic field. I still want to have a small cosmetic payload so I'm asking how can I maximise the magnetic field density where it levitates about 1-3mm above the magnets' surface? I know objects with high permeability can shape magnetic fields, so if I place the magnet track on a sheet of metal with high permeability, will it intensify the field strength in the area the graphite levitates, supporting better levitation and a better payload? If so, looking at this list on wikipedia, will higher permeability work better? e.g using Mu-metal would be better than electrical steel which would be better than normal steel?