In a 3D printing method, a coalescent dispersion for forming a 3D object is selected. The dispersion includes an aqueous vehicle and an infrared or near-infrared binding agent dissolved or dispersed therein. The binding agent is a phthalocyanine having a polar group attached to each side chain or a naphthalocyanine having a polar group attached to each side chain. A sinterable material is deposited and heated to a temperature ranging from about 50 C to about 350 C. The dispersion is selectively applied on at least a portion of the sinterable material. The sinterable material and the dispersion applied thereon are exposed to infrared or near-infrared radiation. The binding agent absorbs the radiation and converts it to thermal energy. At least the portion of the sinterable material in contact with the binding agent is at least cured to form a first layer of the 3D object.
