The present invention provides an aqueous opaque coating formulation comprising (A) and aqueous solvent; (B) an inorganic material; and (C) a chelating polymer which comprises units derived from one or more aminocarboxylate compounds or their salts, one or more other polymerizable monomers, one or more ethylenically unsaturated monomers and, optionally, one or more crosslinking monomers. For example, the aminocarboxylate compounds or their salts may be one or more of iminodiacetic acid (IDA), iminodisuccinic acid (IDS), ethylenediamine triacetic acid (ED3A) and ethylenediamine disuccinic acid (EDDS), or their salts. Suitable polymerizable monomers may be one or more of glycidyl methacrylate (GMA), allyl glycidyl ether (AGE), vinylbenzyl chloride (VBC), allyl bromide, and their derivatives. The inorganic material may be a pigment, such as titanium dioxide (TiO2) or cadmium sulfide (CdS), or an extender or filler, such as talc (Mg3Si4O10(OH)2), calcium carbonate (CaCO3) or mica, or even combinations thereof.