(Phys.org)—Researchers have demonstrated that obvious ink containing gold,silver, and magnetic nanoparticles can be easily screen-printed onto various types of paper, and with the nanoparticles being so small that they seep into the paper's pores. Although invisible to the bare eye,the nanoparticles can be detected by the unique ways that they scatter light and by their magnetic properties. Since the combination of optical and magnetic signatures is extremely difficult to replicate, the nanoparticles have the potential to be an ideal anti-counterfeiting technology.
Source: phys.org