I decided to make a painted metal sign for a friend, based on an image I found on the web.
Step 1: Pick Out an Image.
This apparently a sign from the restroom in a restaurant somewhere in Israel. I have no idea where it is, or who took the picture. But it's neat.
Step 2: Pick a Substrate.
I used this nice metal coffee sign I picked up at the craft store. Anything flat and signlike should suffice.
Step 3: Prep and Paint the Background.
I did a little sanding to even out the surface, then threw on a few coats of primer, let it dry, sanded it smooth, put on another coat of primer, let it dry, and then hit it with a few nice coats of gloss white.
Step 4: Make the Masks.
I did this the hard way since I was hoping to have a professional sign shop do the work. I imported the image into Canvas, autotraced it, then tweaked it until I had a line-art of the sign. If you're going to do the do-it-yourself route that I eventually took, it would probably be just as easy to print out a few copies of the image in the appropriate size. Here I have taped the image for the black parts of the sign to a piece of cardboard.
Step 5: Cut the Mask.
I covered the image with some translucent low tack see-trough adhesive paper, then traced the image out with a sharp knife.
Step 6: Stick the Mask Onto the Sign and Paint.
Here's the mask all cut out and then adhered to the sign. I then sprayed on the black, let it dry a bit, removed the mask, and then repeated the process for the red layer.
Step 7: Voila
Peel off the final layer of masking and let it dry.