Naked Raku the techniques
In naked raku, John takes a burnished piece of bisque fired pottery and puts a slip over its surface.
This slip is used as a barrier between the pot and the glaze so that they will separate from the pot after firing.
The fracturing action of the slip/glaze layer when penetrated by smoke leaves a soft crackle finish stained into the pot's surface.
This is striking yet subtle in comparison to crackle raku glaze.
At this point, you can do some carving through the slip / glaze surface so that when it is reduced post firing, what you carve will show through with black lines. John usually scribes some free-form loops, lines and lets the slip / glaze dry on the pot completely before it's fired.
A saggar is a protective chamber used to contain a delicate piece of pottery.
The concept of firing within a saggar originated with the ancient Chinese in an effort to protect a glazed pot from the ash and grit that is normally dispersed in a wood kiln.
Today the purpose of the saggar is quite different. The bisqued pot is placed in the saggar along with combustible materials to be exposed to the pot during the firing; no glaze is used. Typically the pot is placed on a base of fine sawdust,
sprinkled with some copper carbonate, red iron oxide, or copper sulfate mixed with salt.
Other items may be draped directly on the pot, such as steel wool or copper wire. Some (more adventurous) potters have experimented with vegetable or fruit peels, and seaweed.
The fuming that results from the materials added to the saggar produce irregular colour patterns on the pot.