weathered look are two coats
When a copper or bronze object is exposed to the elements, it develops a gorgeous green patina called verdigris (VER-duh-grease). The technique described here can be used on most any material, including terra-cotta, plastic, or metal, but will look most convincing on items with cracks, crevices, and raised details. If you are unsure of the look to expect, do a trial run on the bottom of your container.
You'll find complete instructions for this faux finish technque below.
2. After the base coat has dried, prepare the top coat. Mix a latex glazing liquid with a second color of latex paint at a ratio of about one part glazing liquid to four parts paint. Then apply this top coat. We used a gaudy aqua here. Paint only a baseball-card-sized area at a time (latex paint dries fast!). Leave irregular edges, then "blend" them.
it is still wet.
3. Right after applying a section of top coat, wad up a rag and blot and dab the paint gently. Soften the edges first, then go over the middle, moving and removing the top coat until you achieve a look you like. When it's all dry, seal with three coats of clear spray sealer.