I make art for coloring purposes and I sell it as PDF documents. There is a lot of piracy and copyright infringement (mostly accidental, but in some cases purposeful) in my specific niche and I would like to know how best to protect myself. 97% of all of my sales are from US citizens, but I am hoping to grow more here at home when I release my book. Customers are allowed to print my PDFs, and they're allowed to color in the images and post their colored images online. They are not allowed to modify the digital file, redistribute the file or printouts, and they are not allowed to sell the file or the printouts (even after they have colored it). How can I protect my PDF files from piracy under Intellectual Property Law? I've added a stamp that says that it's created by me and has a copyright symbol but I'm not sure if that's worded right. How do I protect it internationally? Do I need to purchase something? If someone takes my work and claims it as their own, I do want the option of pursuing legal action but money is a huge factor so I would really love some help or leads.