Similiar tech was used for screeners to try and track leakers. https://en.m.wikipedia.org/wiki/Screener_(promotional) https://en.m.wikipedia.org/wiki/Screener_(

Similiar tech was used for screeners to try and track leakers. https://en.m.wikipedia.org/wiki/Screener_(promotional) https://en.m.wikipedia.org/wiki/Screener_(promotional) Printer Tracking dots is another example. https://en.m.wikipedia.org/wiki/Printer_tracking_dots https://en.m.wikipedia.org/wiki/Printer_tracking_dots For those interested in modern solutions. Look at watermark researchpapers.r