#CoSoSec

Researchers develop unique printing technology for 'invisible' images.

The ability to produce images invisible to the naked eye is due to the creation of special colloidal ink based on nanoscale cellulose particles capable of orienting themselves on a surface in a special manner.

These watermarks could potentially be used for added security of products, banknotes, tickets, and similar items.

https://phys.org/news/2020-09-unique-technology-invisible-images.html

Paper

https://pubs.acs.org/doi/10.1021/acsami.0c11846