I've made a lot of different sizes of hypertufa since that first visit, but I return over and over these three rectangular troughs, all cast from my reusable plywood molds. These troughs were all cast last fall and are fully cured.
Large trough 29 L x 16 W x 12" H
Small trough with rim 17 L x 13 W x 10" H
After 20 years as a professional art handler, I have a real appreciation for crates with skids that allow a forklift access. I like to think of these troughs as having that same sort of utilitarian aesthetic.