Described is a high solids coating composition having exceptional rheological properties and appearances comprising (a) a thermosetting binder, (b) from about 0.1 to about 10 wt. % based on binder solids of solid polyurea particles prepared by the reaction of a mixture of a polyisocyanate and an amino reactant comprising a primary or secondary monoamine that optionally has a hydroxyl or ether group or both, and (c) from about 5 to about 20 wt. % based on binder solids of a cellulose mixed ester having a number average molecular weight of from about 1000 to about 5600, a polydispersity of from about 1.2 to about 3.5, and a total degree of substitution per anhydroglucose unit of from about 3.08 to about 3.5.