A process for preparing composite particles of a powder coating composition comprising the steps of: a. providing a first particle component comprising a plurality of first particles, wherein the first particles comprise a film-forming resin having a glass transition temperature (Tg); b. providing a second particle component comprising a plurality of second particles different from said plurality of said first particles; c. mixing the first and second particle components to form a particle mixture under conditions such that the first and second pluralities of particles form a plurality of individual particle clusters comprising associated particles; d. fluidizing the individual particle clusters in a gas flow having a gas flow temperature; e. while the individual particle clusters are fluidized in a gas flow, subjecting the fluidized particle clusters to a heating event by causing the fluidized particle clusters to flow through a heating zone under conditions effective to fully melt the film-forming resin and fusingly associate clustered particles to provide a plurality of composite particles wherein the heating zone of a treatment apparatus is at a temperature greater than the temperature of the gas flow and greater than the Tg or the melting point of the film-forming resin, wherein the temperature of the heating zone is at least 5.6°C (10°F) greater than the glass transition temperature or the melting point of at least one of the particle components and wherein the heating zone is at a temperature of from 10°C (50°F) to 815.5°C (1500°F) and the heating event occurs for a time period sufficient to fuse the first particles to the second particles, wherein the duration of the heating event is 0.1 seconds - 5 minutes and wherein a heat source independent of the gas flow contributes heat energy to the heating zone. a. providing a first particle component comprising a plurality of first particles, wherein the first particles comprise a film-forming resin having a glass transition temperature (Tg); b. providing a second particle component comprising a plurality of second particles different from said plurality of said first particles; c. mixing the first and second particle components to form a particle mixture under conditions such that the first and second pluralities of particles form a plurality of individual particle clusters comprising associated particles; d. fluidizing the individual particle clusters in a gas flow having a gas flow temperature; e. while the individual particle clusters are fluidized in a gas flow, subjecting the fluidized particle clusters to a heating event by causing the fluidized particle clusters to flow through a heating zone under conditions effective to fully melt the film-forming resin and fusingly associate clustered particles to provide a plurality of composite particles wherein the heating zone of a treatment apparatus is at a temperature greater than the temperature of the gas flow and greater than the Tg or the melting point of the film-forming resin, wherein the temperature of the heating zone is at least 5.6°C (10°F) greater than the glass transition temperature or the melting point of at least one of the particle components and wherein the heating zone is at a temperature of from 10°C (50°F) to 815.5°C (1500°F) and the heating event occurs for a time period sufficient to fuse the first particles to the second particles, wherein the duration of the heating event is 0.1 seconds - 5 minutes and wherein a heat source independent of the gas flow contributes heat energy to the heating zone.