These melamine particles are crosslinked by acid-catalyzed reaction with formaldehyde. The particles have a much higher density (1.51 g/cc) than polystyrene, are hydrophilic with amine and methylolamine groups, and, being crosslinked, are not noticeably swelled by organic solvents. The particles can be lyophilized and then redispersed in water. The particles are supplied as a suspension of 2.5% solids in water.

~1.00µm