I'd go with a spin coating, easiest to create. However coming up with a material that could be easily spin coated that would be a bit harder. There is a lot of math involved [1] :-). There was an excellent "Secret Life of Machines"[2] video about tape which made magnetic tape by sprinkling ferrous oxide (rust) over "sticky tape" (which in the US is often called 'Scotch Tape' as that is the dominant brand).

[1] http://ecee.colorado.edu/~mcleod/teaching/EandM3400/Lab%20Bo...

[2] http://www.secretlifeofmachines.com/secret_life_of_the_video...