Patent ID: 7867555

Claim:
A method, comprising: extruding a base powder mixture to form a base powder with a particle size of 10 to 300 microns, wherein the base powder mixture comprises a carboxyl-functional polyester resin curable with an epoxide-functional compound; mixing said base powder with at least one stable colorant dispersion below about 40° C. to form a colored mixture in which particles of the base powder are coated with a colorant and there is a minimal change in the particle size of the base powder particles, wherein the stable colorant dispersion consists of at least one of a pigment and a dye in a liquid carrier, wherein the liquid carrier is selected from water, organic solvents and combinations thereof, and wherein the liquid carrier does not cause melting or softening of the base powder, and wherein the pigment is selected from organic pigments with a median particle size of less than 0.3 microns, titanium dioxide pigments with a median particle size of 0.3 to 0.5 microns, iron oxide pigments with a median particle size of 0.2 to 0.6 microns, carbon black pigments with a median particle size of about 0.07 microns, and phthalocyanine blue pigments with a median particle size of about 0.05 microns; and treating the colored mixture at temperatures below the softening point of the base powder to form a free flowing powder.