Hello all, I need to make a magnetic surface using neodymium disc magnets... the purpose for the surface is to hold on to a sheet of ferrous material, as strongly as possible. I tend to want to assume that a checkerboard array would be best... alternating the poles of the magnets in the array, so that the closest neighbors of each magnet are in the opposite orientation. Imagine one inch diameter magnets secured in a machined aluminum plate... a 1/8" plastic sheet covering them... the ferrous sheet would then be on the top of that. So the strength needs to be understood in terms of the spacing as well, in case that makes a difference. Also, should the magnets be touching at their edges, or should there be some space in order to maximize the field strength across the array? Thank you ever so much.