Laser-markable compositions
A laser-markable composition comprises a binder and an oxyanion of a multivalent metal.
1. A method for providing black bar-coding on a substrate, which comprises:
applying a formulation to a portion of the substrate that is less than the entire substrate, thereby leaving a portion of the substrate exposed, wherein the formulation comprises one or more components that form a black image on irradiation with laser light; and
irradiating the portion of the substrate to which the formulation is applied, while the exposed portion remains exposed,
wherein the substrate comprises a white pigment, and
wherein the black bar-coding has grade A or B contrast with respect to the white pigment.
2. The method according to claim 1 , wherein the formulation includes a component that absorbs laser light.
3. The method according to claim 1 , wherein the substrate is a polymeric film.
4. The method according to claim 1 , wherein the substrate is metal.
5. The method according to claim 1 , wherein the substrate is paper or cartonboard.
6. The method according to claim 1 , wherein the substrate is an item of packaging.
7. The method according to claim 1 , wherein the substrate is cartonboard.
8. The method according to claim 1 , wherein the black bar-coding has grade A contrast with respect to the white pigment.
9. The method according to claim 7 , wherein the black bar-coding has grade A contrast with respect to the white pigment.