A method of modifying a non-magnetic surface to become magnetic enables magnetic puzzle pieces to be assembled thereon. The invention also includes the resulting modified article, which may be portable, enabling the magnetic lap desk to be transported from palace to place, including transportation by young children. A magnetic paint or primer is used to convert at least the top surface of the lap desk or other article. A further advantage of the invention is that since a user applies the paint or over-coats, different proprietary colors and/or designs may be achieved.