(Updated 20200602) Make PDF Very Hard to be Copied

Step by Step

  1. Google Slides
  2. PDF (text can be copied)
  3. https://pdf2png.com/
  4. PNG
  5. https://png2pdf.com/ (max 20 images)
  6. https://www.ilovepdf.com/merge_pdf
  7. PDF (text can not be copied)