Altering Scanned PDF
I am trying to emphasize certain sections of a scanned PDF document in Preview. I assume that it's impossible to highlight, so I tried using the toolbar to choose a rectangular shape, line thickness and color in order to draw a box around the paragraph. I can see the rectangular box on my screen (not in color), but each time I hit "enter" it disappears. Suggestions PLEASE!
MacBook Pro 13″, macOS 11.1