Being fairly new to the potter's world, I knew that I needed to factor in that my completed pieces would shrink, but I didn't know how much. I recently made a matching desert plate set and now that they are dry, they look more like saucers. So it got me thinking, what are the factors that affect clay as it dries?
One of the key factors is obviously how wet the clay is. I use a lot of water! And the more water you use, the more your clay will absorb and thus the more it will shrink.
I have had a number of bottoms crack on me and kept thinking maybe I was leaving water in the bottom, however I have discovered that although that does indeed cause cracking, the reason behind my failing bottoms was that they were not drying at the same rate as the rest of the piece. The top would be almost completely dry and the bottom, being flat on the table, would still be soft.
- The thickness of your piece
Although my reasoning behind this is the same as the above bullets, in my mind it is a separate factor I take into consideration... how thick is my piece? If I am making a large, thick, sturdy pitcher for example, it will hold more water because there is more clay. Now, this goes back to the first bullet, I have seen potters make large vases with hardly any water. In that case, I would throw this bullet out the window. But because I still soak my sponge every couple minutes... my pieces are wet. And this is a big variable for me. I made a large pitcher that turned out to be too big for a milk/syrup dish and far too small to hold any liquid. It just kept shrinking and shrinking. Hmmmm. Back to the drawing board!
As you can see, there are a number of factors that affect how your piece dries and therefore how it shrinks. I plan on doing a little more forplanning next time and hopefully using a little less water!
