Clay coated paper is paper that is made with a finish of clay that makes the paper shiny.
I was cleaning the page using dry methods such as sanding and scraping and maybe erasing. There were marks on it that may have been dirt. I have other courses on cleaning pages.
Course 3-103 shows how to repair losses. Apparently I started a video for this particular plate and then did not follow through. Possibly because I remembered I had already made such a video. It is hard to keep track! I will look around and see if I can find what I started too.
So glad you are asking questions. Cheers.