This package comes with two sheets of pressure-sensitive plastic (also known as Velostat or Linqstat), each sheet measuring 9.8 in x 9.8 in (250mm x 250mm). When you press on the material, the resistance goes down depending on how hard you press.
These conductive plastic sheets are perfect for making DIY pressure sensors and adding a gentle fade in and fade out effect to your project. Just sandwich a piece of this material between your paper switch to turn it into a pressure sensor!
Here's a video of some fun circuit tricks you can make with pressure sensors:
What to learn more? Here's a tutorial to get you started: