

to really hammer home this “many ways to hide”: the PDF is kinda just like a container… it contains other things like images (the patterns for example)… these patterns are probably vector graphics (made up of lines rather than pixels)… this means you can magnify them basically infinitely… and they can contain transparent lines and all sorts of things. they could easily embed that same text in the SVG image, at tiny scale (less than a pixel at 100% scale), and make it transparent… no PDF editor is going to touch the image data: it simply doesn’t really understand it to that degree - it’s an image; not a PDF after all… so that information will remain even after you’ve removed all visible/reasonable marks
this is just 1 example of practically infinite places it could be - and remember, this text is just lines in an image! it’s not like you can ctrl+f for the text necessarily… you’d have to go through every image manually and inspect every single line, and even then there are no guarantees (perhaps they encoded that information like morse code in bumps in some lines that are only barely visible at 1000% magnification)





+1 davinci… it’s incredible what you get in the free version, and the studio version is getting more and more worth the money in a value add way rather than a need it way