According to examples, an apparatus may include a processor and a memory on which are stored machine-readable instructions that when executed by the processor, may cause the processor to access data corresponding to a 3D object model, in which the data may identify a label placeholder on the 3D object model. The processor may also access fabrication information pertaining to a 3D object to be fabricated based on the data, generate a defined label based on the accessed fabrication information, and may insert the defined label at the label placeholder on the 3D object model, such that the 3D object may be fabricated with the defined label positioned at a location on the 3D object corresponding to the label placeholder on the 3D object model.