Additive manufacturing includes successively forming a plurality of layers on a support. Depositing a layer from the plurality of layers includes dispensing first particles, selectively dispensing second particles in selected regions corresponding to a surface of the object, and fusing at least a portion of the layer. The layer has the first particles throughout and the second particles in the selected regions. Alternatively or in addition, forming the plurality of layers includes depositing multiple groups of layers. Depositing a group of layers includes, for each layer in the group of layers dispensing a feed material to provide the layer, and after dispensing the feed material and before dispensing a subsequent layer fusing a selected portion of the layer. After all layers in the group of layers are dispensed, a volume of the group of layers that extends through all the layers in the group of layers is fused.