I made a hollow form from a piece of satin walnut that I prepared earlier and set aside to dry.
First I mounted the wood with a faceplate on the lathe and turned the outside like that, then I attached the hollow form with a glue block and hollowed it out like that.
I finished the hollow form first with two layers of sealer and light sanding in between, and then sanded to 600 grit and finished with friction polish.
The hollow form has a diameter of 24 centimeters and is 7 centimeters high.