Using an existing piece, glass or metal, as a mold has never been my favorite way to work. It seems too...what?...derivative, I suppose. So often all of the details are just impressions of a surface some other designer created. Why should somebody else have all the fun? When I found this silverplate oval platter with no texture or detail at Augusta's new Goodwill store, I saw a solution to both my problems. Because it is a featureless piece, I can go to town on it.
I made a texture roller using a fat piece of dowel from Home Depot, and a hot glue gun. Advice: if you are purchasing a hot glue gun for this project, get the more expensive one. I got the little $2.99 special, and found that it squirted out so little glue at a time that keeping a steady line was impossible.
Still, I managed a spiral design. I stretched out a slab, about 1/4 inch thick - I hate a flimsy feel to my pottery. Then I rolled the decorative roller over it, in several directions, so the rough quality of the drawing became a non-issue.