A new method for depositing nanoparticles of silver onto paper has the potential to enhance food safety by inhibiting microbial growth. The study, reported in the journal Langmuir, describes a process that uses “ultrasonic radiation” to deposit the silver nanoparticles. Fine silver particles have previously been used as a microbial inhibitor on substrates including cloth, plastic and metal. The study reports that the process made a silver coating penetrate the paper to a depth of one micron, establishing a stable coating. The new process could potentially enable the production of paper and paperboard packaging that fights microbes.