I first heard about combining clay with nails many years ago from Jerry Caplan. Since then I've incorporated nails, screws, forks, and auto parts in past work, so I figured that nails would be especially appropriate for houses and decided to give it a try. Experience has shown me that common steel or box nails work well. I shorten nails with a bolt cutter. Since the nails are actually a visual enhancement, attention should be paid to their placement and appearance.
Heads provide accents or can be cut off with the bolt cutter.
Duplex-head nails have two heads and sometimes two heads look better than one. Finishing nails have small heads and are not as prominent as nails with larger heads. As for color, nails will turn nearly black when fired. They can be painted with acrylic paint afterward if desired. After bisque firing, the design was sketched onto the form with pencil, then several coats of underglaze shading were airbrushed over clear plastic stencils.