4 - Preprinted bar code tag. The recent development of using a C02 laser to blacken a white coated stainless tag makes on-site tag printing more reliable because no ribbons or contact print heads are required. The special laser markable coatings are blackened deep into the coating, thereby providing robust markings which weather well. This permits an inventory of stacked slabs if the tags are placed in a position where they may be safely scanned while stacked. Similar approaches could be used with bar coded tags.
Concerns remain over losing tag identification if the band breaks or drops off.
Abbreviated paint marks or dot peen markings could be added to permit manual recovery of the product's identity if the band is lost. 6 - Tag with band slots. Some mills consider that side nailing on slabs can produce defects in the rolled products. End nailing may be preferred since this area is often sheared prior to rolling. Virtually all nailing is done manually.