Rubber marking spans raw compound, semi-finished, and finished stages, and traceability often spans all three. Tires require the most complex marking of any rubber product; hoses and belts are made by continuous extrusion demanding non-contact in-line coding. Drivers are batch/spec traceability, tire DOT compliance, and pre/post-vulcanization traceability. Two physical realities govern selection: black carbon-filled surfaces have almost no contrast, and pre- and post-vulcanization are two distinct coding windows with different surface properties.