====== PDF Customize ======

  * PDF - disable print, copy
    * Ctrl + D in acrobat pro, in security, choose password security
    * in Permission, check restrict editing and printing (none for both print and change, uncheck enable copying, optional disable enable text access, then put a password)
    * save as
  * PDF - outline text (ref: https://www.w3pedia.com/uk/convert-text-to-outlines-in-adobe-acrobat)
    * in watermark tool, add a placeholder 0% watermark on top of all page, 
    * in acrobat tool panel, add "Print Production" button, and click open,
    * right panel, click "Flattener Preview", check Convert all text to outlines, all strokes to outlines (w bottom "all pages in documents")

====== PDF Edit in Acrobat Pro ======

  * Add Image with same size:
    * there is no way to set exact size, but if you Edit> Add image, your image size will be in ratio of your current image size,
    * if you zoom in pdf, when you place image, the image will be bigger in ratio
    * so you can make sure all your image is in proportion in image pixel size
    * then zoom in pdf at right level, add image in, so they will be all at certain size with same scale ratio
    * ----
    * if above not work well, you can try copy 1 image, and paste to another place, then replace that image, it will maintain same size

====== Combine of Image or Combine of Vector PDFs ======

  * if you have original illustrator design or indesign pdf file, it is better to combine those files into another Big PDF
  * as the jpg,png images will pixelated when zoom in, as those text in image wont auto high res itself comparing to those vector graphics version of pdfs