Around 2008 I was interested with improving exteriors of glazed pottery and thought that if glazes were scratched then decorations could be applied, much like decorating emu eggs. I took a dremel tool with a diamond tip and scratched this design on the rim. I think it turns out better if a Sharpie is used first, then engraved over/thru the design. It appears to be etched!. Works with dark glazes.