Yes, according to the reference provided, colored slip can be applied to bone dry clay.
Applying Slip to Dry Clay
The application of colored slip is a versatile technique in pottery, and its timing depends largely on the desired effect and the properties of the clay body being used. As stated in the provided reference:
They can be applied to wet, leather-hard or dry clay bodies, depending on the technique being used and the dry strength of the body.
This indicates that applying slip to "dry clay bodies," which includes bone dry clay, is a viable option.
Key Considerations
Applying slip to bone dry clay differs from applying it to wetter stages and requires attention to specific factors highlighted in the reference:
- Technique: The method of application (brushing, dipping, pouring, etc.) might need adjustment when working with fragile dry clay. Some techniques might be too abrasive.
- Dry Strength: The inherent strength of the bone dry clay body is crucial. Some clay types are very brittle when completely dry and may not withstand the moisture introduced by the slip without cracking or crumbling.
Application Stages for Slip
Slip can be applied at various stages of the clay's drying process:
- Wet: Applied when the clay is soft and pliable.
- Leather-hard: Applied when the clay is firm but still holds moisture.
- Dry (Bone Dry): Applied when all physical water has evaporated, and the clay is at its most fragile unfired state.
Here's a simple overview:
| Clay Stage | Application Viability | Considerations |
|---|---|---|
| Wet | High | Blends easily, can be scratched through (sgraffito) |
| Leather-hard | High | Holds crisp lines, good for carving |
| Dry | Possible | Requires careful technique; depends on dry strength |
What Happens After Applying Slip to Dry Clay?
After applying slip, the piece is typically allowed to dry completely again before being fired. The reference notes the typical next steps:
The slip decoration usually is covered with a glaze after bisque firing, although many people prefer to leave the slip patterns unglazed.
So, whether applied wet, leather-hard, or dry, the piece would generally undergo a bisque firing, after which a clear or colored glaze might be applied over the slip before a second firing, or the slipped areas might be left unglazed.
In summary, while challenging and dependent on the specific clay and how it's handled, applying colored slip to bone dry clay is possible according to standard practices in ceramics, as supported by the provided information.
