Developing a Slipped Surface

Slip is basically liquid clay. In this case, a specific formula of ceramic materials I've chosen for their specific properties. I've decided to color this first coat of slip with a specific ratio of  iron oxide and cobalt carbonate for a dark reddish brown once it's fired. The consistency of my slip is like buttermilk for this particular application. I'll lay on a variety of other colored slips over this, as well, not unlike the way I do an underpainting when I'm oil painting.