An ink including stabilized magnetic single-crystal nanoparticles, wherein the value of the magnetic anisotropy of the magnetic nanoparticles is greater than or equal to 2×104 J/m3. The magnetic nanoparticle may be a ferromagnetic nanoparticle, such as FePt. The ink includes a magnetic material that minimizes the size of the particle, resulting in excellent magnetic pigment dispersion stability, particularly in non-aqueous inkjet inks. The smaller sized magnetic particles of the ink also maintains excellent magnetic properties, thereby reducing the amount of magnetic particle loading required in the ink.