With just under two weeks before I announce the next piece in my Sculpting Mythology series, I thought to share a technique from another part of my life that I have yet to discuss on this blog. 2-3 days per week, I work as an historical presenter and decorative artist at The Henry Ford’s Pottery Shop.
The Pottery has a line of around 250 different items. We make in excess of 10,000 pieces each year, go through a ton of clay per month and have a staff of seven. It is a production shop that supplies THF’s gift stores, catalogs, historic buildings and restaurants but we also demonstrate how pottery was made in North America from the colonial era through to the twentieth century. In fact, some of the equipment we use is of historical interest in its own right – including a belt-driven potter’s wheel from the 1870s.
One of my favorite techniques to demonstrate is sgraffito, which most commonly took the form of decorative plates. German immigrants brought the style with them to the new world and it was popular in North America during the 1700’s and early 1800’s. A time consuming (and expensive) technique, you would not have seen a set of these around the dining table of a colonial home as much as a single plate hanging over the mantle – likely a cherished wedding gift.
Sgraffito comes from an Italian word meaning to scratch or scrape and this describes precisely the technique.
I start by drape-molding a red ware plate over a plaster form to ensure consistency in size and shape. I then pour a paper-thin coating of slip (watered down clay) onto the inner surface of the plate and allow it to dry to the touch – a process that takes 3-5 days in a damp cabinet. [note: The slip appears gray but will fire to a buttery yellow.]
Once the proper level of moisture in the clay has been achieved (referred to as leather hard), I trim the plate on the potter’s wheel and then use simple loop and needle tools to carve my design through the top layer thereby revealing the red clay beneath.
The carving completed, I allow it to dry fully in the open air for about a week. At this stage, the surface must be gently sanded using nylon netting and any dust or debris cleaned off with an air compressor. Next, I selectively brush on a highly diluted copper paste that will turn green when fired.
The finished piece gets fired twice at 1800-2000 degrees Fahrenheit with a coating of clear glass frit (glaze) applied between firings.
The process takes about 30 days from clay cabinet to store shelf.
Greenfield Village and the Liberty Craftworks (part of The Henry Ford in Dearborn, Michigan) will reopen to the public for the 2014 season on April 15. If you happen by the pottery, stop in and say hello!