A novel aqueous polymeric formulation is disclosed. Also disclosed are methods of making the polymeric formulation, and of using the polymeric formulation to produce a crosslinked polymeric surface coating on a substrate. One embodiment of the novel polymeric formulation comprises an aqueous carrier; at least one polymeric ingredient; a non-polymeric polyfunctional amine; and base. The one polymeric ingredient has both acid-functional and acetoacetoxy-type functional pendant moieties. The non-polymeric polyfunctional amine has at least two amine-functional moieties. The amount of base contained within the formulation is effective for inhibiting gellation, which would otherwise occur as a result of crosslinking between the acetoacetoxy-type functional and amine-functional moieties. Another embodiment of the novel polymeric formulation comprises at least two polymeric ingredients, one of which has acetoacetoxy-type functional pendant moieties and the other of which has acid-functional pendant moieties.