An air drying auto-oxidizable resin composition comprising components: a) a drier comprising a manganese salt complex, and b) a polymer comprising unsaturated fatty acid residues, wherein the manganese salt complex has the following structure I: wherein the anion is selected from Cl−, NO3− or R2COO−, in which case n=2; or the anion is SO42−, in which case n=1; wherein X,Y,Z are independently selected from O, OH, OH2, OC(R3)O, and R4BO2 and wherein a and b are independently an integer of value 2, 3 or 4; R1═H, C1-C20 alkyl optionally substituted with heteroatoms, C6-C20 aryl optionally substituted with heteroatoms; R2=C1-C20 alkyl optionally substituted with heteroatoms, C6-C20 aryl optionally substituted with heteroatoms, or a polymeric residue; and R3=C1-C20 alkyl optionally substituted with heteroatoms, C6-C20 aryl optionally substituted with heteroatoms, or a polymeric residue. R4═C1-C20 alkyl optionally substituted with heteroatoms, or C6-C20 aryl optionally substituted with heteroatoms.