An apparatus and method for shimming a magnetic field of a magnet in a volume of interest includes a nonmagnetic holder configured with an array of fluid containing pockets; and a solidified ferromagnetic fluid in each pocket of the array of fluid containing pockets, wherein the solidified ferromagnetic fluid is fabricated from a ferromagnetic fluid, a diluting liquid, a hardener, and an accelerator agent. The ferromagnetic fluid includes a carrier liquid, ferromagnetic particles, and a surfactant.