Do you remember this stuff from your 5th grade science class? Some kind of property makes it a liquid and a solid at the same time. As long as you apply pressure to it, its a solid, but the moment you let go it slithers through your fingers like a liquid.
All you do is mix cornstarch and water, (i just eye-balled it) and food coloring. Mix until thick and a little runny at the same time - sounds weird huh?? R played with this for almost an hour. I had to add a little more water to it during her play, because it dries out as its exposed to air. I put her outside, so that I could just hose the little table down (2$ at a garage sale by the way) when she was done.