Continental Currency Paper?

I did a quick google search...https://www.pmgnotes.com/news/artic...paper-types/

I've read some old advertisements from that era for unwanted rags to be made into paper for printing purposes, including banknotes. When I got my first colonial notes, which used the same paper making methods, I was wondering if they were counterfeit, as there were sparkles embedded in them. Then I read that the inclusions were flakes of mica used as a counterfeit deterrence. some notes have a few blue fibers mixed in both colonial and continental notes as well.