Ceramics is a craft that requires learning techniques that are unique to working with clay. The clay goes through the processes of handbuilding, decorating and firing before the piece is complete. In ceramics, the clay is shaped into vases, figures and models, then fired in a kiln and decorated. One of the basic techniques learned by ceramic students is score and slip. Score and slip allows the artist to join two pieces of clay together using nothing but the clay and water.
Slip is liquid clay made from adding clay dust to water and stirring it vigorously to avoid thickening. The finished product is the consistency of heavy cream or oatmeal. The purpose of slip is to act as glue to hold the slabs of clay together. Apply slip with a paintbrush to areas of clay that have already been scored. Use slip in place of water because it forms a stronger bond. Slip is also used to decorate pottery by painting the pottery with the slip and letting it dry, creating a two-tone look.
Scoring clay involves slicing small notches into the clay with a sharp tool. Use any sharp object, including a knife or even a fingernail. Pottery stores sell special needle tools and scratch wire brushes for scoring. The scored notches are shallow and indented, creating space for the slip. They are slathered with a dab of slip, then another slab of clay is attached. Both pieces of clay are scored before they are joined together.
Slip and Score
The slip and score process begins with two unfired slabs of clay. The clay used for scoring and slipping should always be leather-hard. Score each piece of clay in the areas where they will be attached, using anything with a sharp edge -- a fingernail works fine for scoring clay. Using a large paintbrush, apply a thick coating of slip to the scored area on one of the unfired slabs. Press the two pieces of clay firmly together for about one minute, stopping when the pieces stay together on their own. Scrape away any slip on the outside of the pieces, and allow them to dry for a few hours. After the slipped and scored pieces are dry, fire the pottery in the kiln.
The slip and score method is used to create many different types of ceramic pieces, but it is especially useful for attaching handles or other small pieces. Use score and slip to attach a handle to a pitcher or a cup. Attach the body parts of ceramic animals by scoring the surface and applying slip. Score and slip the four sides together to create a ceramic box. There are other ways to make clay pieces adhere to each other, but score and slip is simple and easy to teach to beginners, so it remains a common method.