It is generally advisable to keep underglaze from coming into direct contact with the kiln’s heating elements or shelves, as it can potentially affect the firing process and cause issues.
Shelf Marks
If underglaze comes into contact with kiln shelves, it may stick to the shelves and cause marks or damage when the piece is removed after firing.
Firing Performance
Underglaze touching the kiln walls or elements can affect the airflow and heat distribution inside the kiln, which may lead to uneven firing and inconsistent results.
Preventive Measures
To prevent underglaze from touching the kiln, consider using stilts or kiln posts to elevate your pieces slightly above the kiln shelf. These supports can help create space and reduce the risk of contact.
Conclusion
Avoiding direct contact between underglaze and the kiln is recommended to ensure a successful firing and preserve the quality of your ceramic pieces.