When I spotted the cute little light bulb style vases in my craft store I knew I wanted to use them in a project. When I remembered the leftover etching cream in my craft stash, I had an idea. 
I made a stencil using contact paper and my Silhouette machine. (Use speed of 8, thickness of 3, blade setting of 1.) You can accomplish the same thing without a Silhouette by using the backing from letter stickers.
Placing the stencil on the bulb is a little challenging, but relatively simple once you get the hang of it. Just focus on the letters and don’t worry about getting the other parts smooth.
I covered the letters with etching cream and waited. And…nothing. Oops! The etching cream just removed the blue paint that was on the outside of the vase. Never one to let a craft fail hold me back, I tried again. I rubbed off the rest of the blue paint with some steel wool and repeated the steps.
Success! I knew etching that bulb would be a good idea!