> > What is the most positive way to block magnetic field using a 5mm *any
> > material* board?
> > Take a look at the picture and tell me why it doesn't work.
> > http://www.ustr.net/jpg/moto1.jpg

Because you can't "block" a magnetic field the way the picture shows..  It
completes, always. There is no substance that can simply block the fields
without interacting with them.

You can shield by using high permeability material, which would be strongly
attracted to the magnets, or by diamagnetic material which is repelled (a
superconductor)  but the field will always complete.