There are many factors that can effect how a piece of work turns out.
Clay issues -
- If clay has not been fully scored and slipped to join different aspects together then cracks may appear along join lines or pieces might fall off entirely.
- If clay is not even in its thickness then stress cracks can occur. This happens as thicker areas of clay take longer to dry then thinner areas placing stress across the piece.
-Clay has memory, when it is handled a lot it can want to revert back to its original shape. This is particularly evident when making large flat or wide objects such as plates which can have high failure rates due to warping.
- All clay shrinks, in order to achieve a specific size a calculation must be done to allow for this shrinkage. The stoneware clay used at the studio has a general shrinkage rate of 12-15%
- Any lumps, bumps, dents that I left in a clay surface when wet will remain once fired. Glaze will not fill dents or cracks as it is fluid during the firing process.
Colour-
-Underglaze colours generally appear lighter before firing has occurred
- Whilst underglazes and stroke and coats can be mixed much like normal paints, because they are pigment based colours, the tones and colour might differ from expectation.
- Almost every brush on glaze requires three thick coats to ensure consistent coverage. Each layer needs time to dry before applying the next.
- Glazes are not pigment based paints, the colour is achieved through chemical formulation - putting a yellow glaze over a blue glaze will not generally result in a green outcome. Glaze layering is only permitted where a test tile has been done first.