Reinventing the wheel

I wasn’t happy with the very light colour of fired raku clay I used for making my bonsai pots and I decided to mix it with an iron oxide to make it darker. An oval pot for one of my junipers made of this clay is shown on the first picture. I had a small leftover of this clay and thought what if I smudge it on the surface of another pot to make it look dark while it is made of the usual light clay. Little I knew that it’s a basic pottery technique and the clay I smudged is called slip. However, it is usually diluted to consistency of a glaze and painted on with a brush. The pot that resulted from my first use of slip is shown on the second picture and it will house a small Black Pine.