While industrial inkjet and thermal transfer printing have been the primary means of marking and coding packaging, laser marking is emerging as a complementary and even competitive technology that can provide both performance and cost benefits to the end user. Conventional laser marking typically relies on high energy processes such as ablation or engraving to permanently mark various materials. The method is limited to those specific substrates that can absorb the laser energy, and many materials cannot be marked unless specialty additives are included during manufacture. Furthermore, the high energies required to generate readable marks can damage thin substrates.A laser responsive surface layer enables on-demand marking of variable data on materials that would otherwise be difficult to mark. Laser responsive inks and coatings are demonstrated which enable high density, stable images to be coded using a low energy IR laser, onto substrates printed or coated by standard methods during the substrate manufacture, printing or converting stage. Transparent or virtual labels that mimic conventional self-adhesive labels can be produced and marked on-demand. The laser responsive inks and coatings are ideally suited for use on food, beverage and pharmaceutical packaging to be marked with variable messages, security identifiers, or tracking codes.