This discussion revolves a lot around printer watermarking documents. It seems that it mostly concern color printers. Here is an advisory by the EFF which teste

This discussion revolves a lot around printer watermarking documents. It seems that it mostly concern color printers. Here is an advisory by the EFF which tested quite a few of them https://www.eff.org/pages/list-printers-which-do-or-do-not-display-tracking-dots https://www.eff.org/pages/list-printers-which-do-or-do-not-d...