Device tagging can be done through printing or usage of lasers. Thermal plaster label printers are widely-used for the tags that are in direct experience of the heat. These tags are designed weather resistant, UV immune, chemical resistant, smudge resistant or heat resistant with regards to the requirement of the merchandise to be described. Metallic inks, magnetic inks or UV inks are also used for tag words. These are usually transparent, but may be made opaque depending upon the needs. Intended for printing tags, the application of PMS colors established fact.