Cover a light bulb with a doily and spray paint it. The light will shine the pattern onto the walls. I'm guessing this is one of those easier said than done, doilies are not light bulb shaped. It'd prob be easier to use doily as a stencil & handpaint it.
Great way to control access to the fire, and prevent too much heat where you don't want it! Just build the back rim of the fire pit surround so it's higher! Backyard fire pit ~ nice for on the edge of a patio.