This vase was fired using a raku method.  Firstly, the vase is burnished to a smooth surface when leatherhard.  Next, it's bisque fired. 
 
It is then ready for the kiln.  Once it reaches a certain temperature, it's removed from the kiln.  When objects such as horsehair or feathers are placed against the crazy hot vase, the carbon burns the image into the clay.  This vase had horsehair and crow feathers burned into it. 
 
After cleaning, it was polished with wax/polish on the outside. 
 
Since raku vessels don't reach vitrification temperatures, they are not water-tight.  This vase, however, was treated with a sealant and should now be watertight. 
 
This was a lot of fun to do.  I was lucky with mine, others had explosive results. 
 
Measures approx 20cm tall.
 
Handcrafted in Cornwall with fun.