Well, with the art show coming up April 12th, he needs to sit on something a little more dignified than this ice-cream-Styrofoam combo kind of seat on which he was created. He will be perched on a plinth, perusing the gallery and those who come to visit. Since "box-seats" seem to be so wonderful, I decided to get him one too.
Since he's in a seated position I measured the back of his leg from heel to bent knee. That gave me the measurement of the height his box needed to be for him to sit on comfortably. Next I pushed the clay through the slab roller and cut the slabs to the correct dimensions. Since the clay was wet, it could not bear any weight nor stand on it's own for making the box. I let them dry for a few days before working with them any further.
The next step was to cut the slabs to size. I had to subtract the height of the slabs by the width of the clay used for the top seat part of the box, so it would be just the right height. I lay that top slab of clay on my worktable and constructed the sides of the box, squared up, right on it. That meant it was in the upside down position, as you see in the photo above. Once in place I scored and welded all the edges together with damp clay. Due to the pressure of the piece that would be sitting on the box I placed a slab in the centre, as a brace for that area of the seat. Also, you can see small rectangles on the inside of the corners, which I placed there just to give these joints more stability and strength. Then I covered the work loosely with plastic waiting for everything to dry uniformly to a leather hard state.

Following this I used a tool to age the chair or make it look a little like a stone carved bench, worn and aged over time.

Above you see the photo of the finished "box seat" sitting on boards drying. The boards give the bottom space for air to move underneath and allow for the seat to dry more evenly and quicker. I will still cover it loosely with plastic so it drys evenly and slowly. It must dry evenly because it shrinks as it dries. If it is uneven in the drying process it will shrink unevenly causing stress cracks to appear. This is not good.
This will be a great "box seat" from which my character can more enjoyably take in all the happenings at the art show where he will be seated.