shrinky dinks! my brother and I had some of those when we were little, but they were pre-made, so all we did was put them in the oven. Or maybe we got to color them too, I'm not sure... but one thing for sure is that we didn't make our own compsitions. That's cool. They look like stained glass.
i couldn't quite tell what it was in the other photo
but yeas I remember the precut and outlined ones as kids. I had smuff ones and rainbow bright.
Next I am making a nintendo charm bracelet.