The use of a formulation comprising a) a graft copolymer of the Formula wherein A are polymerizable monomers or comonomers selected from alkyl vinyl ether, phenyl vinyl ether, allyl ether, acrylate, methacrylate, propylene, butadiene, maleic anhydride or styrene; m represents a homopolymer or copolymer or a mixture thereof containing one or more monomers A and being the graft backbone and being selected from poly alkyl vinyl ether, poly phenyl vinyl ether, poly allyl ether, polyacrylate, poly methacrylate, poly(alkyl vinyl ether- co -acrylate), polypropylene, polybutadiene, alkyl vinyl ether-maleic anhydride copolymer or polystyrene; n represents the units in the backbone m+n where a branch is grafted from the unit in the backbone; Y are polymerizable monomers or comonomers selected from (meth) acrylate, styrene, vinyl acetate; p is a grafting chain which is a homo/copolymer of one or more monomers selected from (meth) acrylate, styrene, vinyl acetate; p = 1-5000; m is a number between 1 - 5000, n is a number of 1 - 5000; and m + n is a number of 30-5000; b) polymer, mixed polymers or copolymer m+n; and c) polymer, mixed polymer or copolymer of the monomer(s) Y; as a defoamer or as one/more components in a defoamer formulation for solvent based coating systems. a) a graft copolymer of the Formula wherein A are polymerizable monomers or comonomers selected from alkyl vinyl ether, phenyl vinyl ether, allyl ether, acrylate, methacrylate, propylene, butadiene, maleic anhydride or styrene; m represents a homopolymer or copolymer or a mixture thereof containing one or more monomers A and being the graft backbone and being selected from poly alkyl vinyl ether, poly phenyl vinyl ether, poly allyl ether, polyacrylate, poly methacrylate, poly(alkyl vinyl ether- co -acrylate), polypropylene, polybutadiene, alkyl vinyl ether-maleic anhydride copolymer or polystyrene; n represents the units in the backbone m+n where a branch is grafted from the unit in the backbone; Y are polymerizable monomers or comonomers selected from (meth) acrylate, styrene, vinyl acetate; p is a grafting chain which is a homo/copolymer of one or more monomers selected from (meth) acrylate, styrene, vinyl acetate; p = 1-5000; m is a number between 1 - 5000, n is a number of 1 - 5000; and m + n is a number of 30-5000; A are polymerizable monomers or comonomers selected from alkyl vinyl ether, phenyl vinyl ether, allyl ether, acrylate, methacrylate, propylene, butadiene, maleic anhydride or styrene; m represents a homopolymer or copolymer or a mixture thereof containing one or more monomers A and being the graft backbone and being selected from poly alkyl vinyl ether, poly phenyl vinyl ether, poly allyl ether, polyacrylate, poly methacrylate, poly(alkyl vinyl ether- co -acrylate), polypropylene, polybutadiene, alkyl vinyl ether-maleic anhydride copolymer or polystyrene; n represents the units in the backbone m+n where a branch is grafted from the unit in the backbone; Y are polymerizable monomers or comonomers selected from (meth) acrylate, styrene, vinyl acetate; p is a grafting chain which is a homo/copolymer of one or more monomers selected from (meth) acrylate, styrene, vinyl acetate; p = 1-5000; m is a number between 1 - 5000, n is a number of 1 - 5000; and m + n is a number of 30-5000; b) polymer, mixed polymers or copolymer m+n; and c) polymer, mixed polymer or copolymer of the monomer(s) Y;