In some examples, a technique includes forming, on a surface of a first layer of material, a second layer of material using an additive manufacturing process. The technique also may include imaging the second layer using a laser imaging device to generate a second layer image. Further, the technique may include determining, by a computing device, whether a thickness of the second layer, in a direction substantially normal to the surface of the first layer of material, is within a defined range of thickness for the second layer.