I while ago I stumbled across the CrossView subreddit. I thought the text CrossView images that contained hidden messages were especially cool. So, I decided to try to create one using simple HTML/CSS. The process was really simple. Check out the codepen below, or view it in fullscreen to better see the effect:
The effect is created by moving specific words on the left text up a couple pixels, and words on the right side down. The greater the offset, the greater emphasis they’re given when crossviewed. For this font and text size, I found that a 4px span worked well.
This could easily be built into a web-based tool to generate text crossview images. I may work on that in the future if there is any interest in that kind of thing.