These are some pretty impressive uses for heat sensitive paint used by Shi Yuan. The poster above reacts when you touch it. The wallpaper reacts to a rise in temperature, and the calendar fades away during the day. It's a wonder why people aren't currently marketing these kinds of things to every day users.
These sweet posters are part of the Hero and Villain series by Simon C. Page. They feature some well known rivalries: Luke Skywalker vs Darth Vader, Batman vs Penguin and Spiderman vs Green Goblin. I especially like the Batman and Spiderman posters which feature the foreground-background optical illusion.