I’ve just updated my page on Building a Scrapbook and tomorrow, the books should be finished.
I’ve also written a bit more in the Problems of the Marbling Kind about paint
Getting the paints balanced perfectly with your size can be very tricky. One of the most obvious problems is having the paint contract into a tiny ball and drop to the bottom of your tray. This happens when the paint is too thick or heavy in relation to the size. The solution is usually to add more water to the paint, a few drops at a time. Alternatively, a surfactant can be added to the paint. … for more see above link.