Every ceramic piece crafted by MacKenzie-Childs artisans is from their signature red clay. There are many different clays to choose from: those with grit (sand to keep fragile clays together), or those without grit; special clay for high-fired pieces (for food and drink) and cheap clay to teach students and children. Different clays can factor in overall use, color, and durability of a piece.
Every ceramic piece by MacKenzie-Childs starts out as a raw form of clay. It is taken out of the earth, filtered, and wedged to become a solid block of clay. Once fired, it can be incredibly durable and resistant to high temperatures. The clay can be molded in any fashion: slipcast, by hand, or machine-pressed. Once formed, MacKenzie-Childs ceramic pieces can be fired up to three times before it is completely decorated. Clay itself takes patience, but so does the process of firing and decorating. It is a very time consuming process.
It all begins in the Mold Shop, where the plaster molds are created for the ceramic pieces. Every MacKenzie-Childs piece starts off this way. Different methods of molding the clay do best for certain shapes. For instance, hand press molds—where pieces are formed by hand—is better for platters and bowls; hydraulic press molds—two plaster molds that are pressed together—is better for knobs, tiles, and dinnerware; and slipcast molds—pouring liquid clay called slip into the mold—is better for hollow pieces like teapots, mugs, and garden balls.
Since a good majority of pieces are hollow, we will go in depth for the slipcast process. The slip is poured from large vats, through a tube, into the mold. Plaster is porous, which allows the slip to dry and hold its shape. The slip dries from the outside in, meaning that the longer you leave the slip in the mold, the thicker the walls of the piece will be. Once the desired width is gained, the artisan will pour out the leftover slip to be reused for another piece. The clay is then allowed to dry more overnight. When the clay comes out, it becomes “leather hard,” which is when the clay is dry enough to be handled without ruining the shape. This stage is optimal for carving and refining a piece before it’s finally fired.
Often when a piece comes out of a mold, edges are left from the two plaster molds. A skilled artisan must hand trim and clean all edges of the piece before he can add anything else. He must also be sure that every angle is smooth so it can’t cut the customer after firing.
Once the piece is finished being refined, the decorative and functional clay elements can be added—like rabbit ears, fishtails, and handles. They cannot be added in the mold because they would be too fragile to break out of the mold. They must be added using slip, extra clay, and a lot of smoothing to ensure the pieces are properly connected and look like they are a part of the piece. If the artisan doesn't apply the elements properly, they can fall apart in the kiln.
The finished greenware (unfired clay) is placed on a rack to dry completely prior to firing. Leather ahrd pieces still retain moisture, and if you put them in the kiln before they are completely dry, they can crack. You have to wait until the piece becomes “bone dry,” which means it’s completely dry to the touch and generally a lighter color than the clay you started with. Now it is time to load the piece into the kiln!
Once the greenware is loaded onto carts, they are rolled into a large kiln. The kiln will operate for about 24 hours until it is ready to be taken out. To properly fire a piece of clay, a kiln can go up to 1,810°F (987°C)—a lot
more than your average kitchen oven. This “bisque fire” is where the clay hardens and becomes more durable. The handle of a teapot can now support the pot’s weight without falling apart. The clay must be allowed to slowly
cool down after firing. If you rush the cooling process, the pieces could explode.
The pieces have been bisque fired, taken out of the kiln, and are now ready to have a layer of wax added to the foot. The wax repels any glaze that it comes into contact with. Keeping glaze off the foot is essential, since the glass particles in the glaze melt from the high temperatures in the kiln. If there is glaze on the foot, the glass particles can fuse with the bottom of the racks and the kiln and efficiently ruin both your piece and the kiln. The wax, however, does not stick to the bottom of the kiln. It eventually evaporates during the firing process, leaving the bottom of the piece in the chalky form of bisqued clay.
After the wax is applied, the piece is dipped in what looks to be a light-pink glaze. Most glazes are not the color you expect them to be before firing. A red glaze can appear brown after firing, and a white/clear glaze can appear pink or orange. This “light-pink” glaze actually turns out to be a glossy white. It’s dunked in the white glaze because the natural color of the clay is red, which can change the intended colors for decoration. The wax repels any glaze that would get on the bottom of the piece while it’s being dunked.
Now an artisan can add decorative elements to a piece. Every ceramic created by a MacKenzie-Childs artisan is hand-painted, making each product unique. The artisans either add many layers of glaze, or only one layer. Applied once, glaze looks a lot like watercolor, where you can see what’s underneath. You would be able to see the streaks of a brush, too. Adding additional layers gives the glaze a more opaque look.
The piece is now ready to be fired again. On the sides of the picture are two glazed pieces that haven’t been fired, and the one in the middle is a glazed piece that has been fired. The glossy shine comes from dense glass particles in the glaze that melt and harden during the firing process. These special glazes allow you to use your piece with food, drinks, or in the oven. It also fortifies the clay underneath, making it stronger and more durable. A lot of clay pieces will have a smooth, glossy surface, but if you look closer, you might see pinholes or other variations in the glaze. Don’t worry, that will not interfere with the use of your product. Each MacKenzie-Childs piece must go through strenuous quality control. If those variations are too large, the pieces cannot be sold. Those pinhole variations occur when natural matter in the clay explodes through the glaze during a firing. It adds personality to the pottery and helps you discern whether your piece is authentically created. The second firing could be the final firing, but for pieces that require more decoration, there is more to come.
After a piece is fired the second time, you can add other decorative elements, like decals (made from glaze), gold, platinum, and copper lustres. This is where patterns that require faux marbling are painted with china paints. The reason why these decorative elements must be added after the second firing is because they must be fired higher than the initial glazes. The initial glazes will stay where they are, mainly because they had been fired already.
Remember how glazes can be a different color than you expect before you fire it? That’s exactly what these lustres do. Once fired, a chemical reaction occurs from the heat and the lustre melts to create the 24 karat gold shimmer.
The piece is fired a third time and—finally—ready to be used. They now can be put in the oven, dishwashed, microwaved, and used countless times. Clay is so time consuming, but that's the main reason why it's so honored. The clay can be hand decorated on every inch of the piece, with layers of artistry, which is what MacKenzie-Childs praises. It allows for each piece to shine on its own, even if it’s from the same collection. It gives the customer the view that every piece is uniquely MacKenzie-Childs. Click Here for the MacKenzie-Childs Collection.