According to one example, there is provided a method of additive manufacturing that comprises obtaining data relating to a 3D object to be manufactured, forming a layer of build material on a build platform, applying a cooling agent in a pattern surrounding a portion of build material to be solidified, and applying energy only to the build material on which cooling agent is applied and to the surrounded portion of build material such that the surrounded portion of build material heats up sufficiently to coalesces, and such that build material on which cooling agent is applied is cooled by the cooling agent and is prevented from heating up sufficiently to coalesce.