The ink is based on turpentine or something similarly nasty. The upside is that it will naturally float on water, which means you don't need 'floater paper' or other paraphernalia to make it work. You drip the ink in the water and the drops will 'explode' into layers of rich, vibrant color. Because the ink is not water-soluble, the colors are really vivid. The results we got were much better than with the Sakura set.
I've made a video of klik marbling a piece of paper. It is here. We're really pleased with how this worked out -- and we'll be getter more colors of this type of ink!