The Nature of Stoneware
We make all our own clay, glazes and decorating colours, which we fire to around 1300°C, in a carefully controlled reduction atmosphere. This combines a richness and depth of quality with permanence and durability, giving us a unique palette.
Stoneware has its own characteristics and iron spots occur naturally in the raw materials and occasionally come to the surface during firing. They can range in size from a tiny freckle (considered acceptable, especially on the back or inside of the piece) to a much bigger mark. They will not affect the function or durability of the pot, and we are very careful to select pieces where they don’t detract from the decoration.
Certain colours can also change depending on the glaze thickness and position in the kiln – this is particularly true with our red! These variations are considered part of the quality and are a unique and desirable feature of Highland Stoneware.
Individual freehand painting is a main characteristic of Highland Stoneware. and our artists are encouraged to innovate and develop designs, and to make each piece different.
Second quality pieces are carefully selected to be fully safe and functional, but there will be minor imperfections in the clay, glaze or decoration. Imperfections may include small iron spots, pinholes in the glaze, small decorative blemishes, and glaze ‘crawls’, to name but a few. When fulfilling an order, you can rest assured that we will never select a piece where we considered any flaw to be an unacceptable distraction from its beauty. As always, bear in mind that each piece is free hand decorated, and no two pieces will be identical.
Some common causes of second quality are:
- Iron spots – A naturally occurring spot of iron may rise to the surface of the glaze during firing, and can appear anywhere. In a second quality piece, these spots may be sightly larger than normally considered acceptable.
- Pinholes – These are very small holes in the fired glaze surface penetrating down to the body below. It is rare for there to be more than just one or two in any piece. This does not affect the clay body itself.
- Crawls – These occur during firing when molten glaze pulls back from the clay surface, leaving bare clay patches. This will not affect the function of our Stoneware pottery as it is fired to a high temperature which creates a vitrified body which is impermeable to water. Our seconds will only ever have very small crawls.
- Decoration – There are several circumstances where an inaccuracy in the hand painted decoration, or the irregular behaviour of our specialist colours can cause unexpected, and slightly less than desirable finish. This is particularly relevant to our copper red glaze…it may appear ‘patchy’ or pale.
- Crazing – A network of fine cracks on the surface of the glaze can appear in our red glaze. Still safe to use.
- Warping – some pieces become misshapen during the firing process. For example mugs may be slightly oval in form, or a plate, when viewed side on, will have a slight variation in height.