Every once in a while I get an idea! Actually it was someone who sent a picture of their work in hypertufa and I adapted it to my process. I call it a mold in a mold. It gives me a chance to mold the inside and outside at the same time.
I have simply taken a dollar store three compartment party tray and taped it to a base then built a simple box to surround it. All the wood is put together with screws and can be disassembled to remove the completed project from the mold. As usual I coat the inside of the mold with vegetable oil applied with a small paint brush which keeps everything from sticking together as it dries.
You can see the finished project is multidimensional and could be used many different ways. My original idea was to include three assorted bags of bird feed and sell it as a bird feeder. With the addition of drainage holes for each compartment it would make a nice container to display an assortment of succulents. The finished project is 16 by 8 with compartments that are 2 inches deep.