The present invention is directed to formulations including a polymer and a plasticizer composition. The plasticizer composition is a blend of an alkyl ketal ester plasticizer and a second plasticizer selected from a cycloaliphatic compound, an ortho phthalate compound, a terephthalate compound, a benzoate ester compound, and a bio-based compound. The plasticizer composition is at least 10% by weight of the total of the polymer and the plasticizer composition.