Abstract: This invention relates to a process for preparing detailed foundry shapes (e.g. molds and cores) used in casting metal articles. The process involves preparing foundry shapes from hollow ceramic microspheres bonded with organic or inorganic binders. The foundry shape is then detailed by machining, cutting, stamping, or otherwise removing material from the foundry shape to provide special shapes, letters, numbers, insignia, machine readable codes, etc. on the surface of the foundry shape. The foundry shapes are used to produce detailed metal castings. This detail can be unique to a single casting to provide a permanent traceable mark for casting identification from the time of manufacture to disposal.