Repousse is the art of forming pattern on metal by pressing a relief from the back. I found thin sheets of metal tooling in one of my crates for summer school and a light bulb went off, carnivale masks! I had my students use mask templates (it is summer school after all), some created their own but most used the templates as a base. They traced the template onto newsprint paper then created a design in pencil on it. After that you place a sheet of metal tooling onto a magazine (to add padding) and you cut and tape down your paper mask drawing. You use a wooden stylus to press the shape and design into the metal and then remove the paper, cut the metal and touch up the design as needed. You can also reverse the repousse and push into the design so that you have a combination of raise and sunk-in lines. Lastly, we colored the metal using Sharpies, embellished with feathers and beads, and painted wooden dowels and blocks. for the base to mount the masks.
Just a word of notice. I used the 'treasure chest' of wood box from Sax which has a ton of perfectly sized wood blocks. I also had packs of various sized dowels and had to pre-drill the holes into the blocks so they would stay put. Hot gluing the dowels to the tops of the wood blocks will not work (trust me, I've tried that too!).