Decoration
There are many ways to decorate pottery. The use of glazes is a decoration in itself.
Several glazes can be applied on one object, creating
interesting contrast in colour and texture.
Glazes can be applied freely with a brush, pots can be dipped in a batch of glaze,
or sprayed using a spray gun and compressor; in this case the use of a booth
is required, making this an expensive way to apply glazes, not suitable for small workshops.
It avoids dribbles and allows layering.
Another way to decorate pottery is to paint ornaments with over or under glaze oxides,
or with enamels and gildings on the fired glazed surface;
this is a technique mostly used to decorate porcelain and such pigments are fired at around 700°C.
Incised or raised decoration can be applied on the raw ware, and looks at its best
when covered with a plain transparent glaze.
Engobes are liquid clay stained with oxides and can be applied by painting or dipping. 
The most common sources of colour for pottery are cobalt oxide or carbonate for blues,
copper oxide for greens or turquoises, manganese oxide for browns and purples
and iron and vanadium oxides for browns and yellows.