Flow agent masterbatch for pigmented powder coatings. Contains 15% of a special additive in an outdoor resistant hydroxylated polyester. An addition of 3-5% on polyester weight gives excellent flow and pigment wetting properties and eliminates any surface defects (craters, pinholes etc.) in sensitive powder coating formulations. It is also used to improve cross-compatibility between different systems (epoxides, polyester/epoxide, polyester, polyurethane and acrylate).