The invention provides a masterbatch preparation process, said process including : - milling a pigment in a mill with one or more of a wax or non-wax polymer; - stabilizing and solidifying the blend by way of annealing; and - solidifying the blend by contacting it with a chilled surface. The chilled surface may be a chilled roller, a perforated sheet or mesh thereby to create elongate elements of solidified pigment blend. The milling may be performed at a temperature of from 50癈 to 250癈. The milling may include one or more heating and cooling zones.