Features Technique: Pottery Glazes

This month we’re going to get a little technical on you, and talk about the difference between pottery and ceramics and high fire and low fire.

First pottery and ceramics: There is no difference. It’s like asking if something is cow or beef. It’s the exact same thing, just different places call things different names. Doesn’t that help?

High fire versus low fire IS a thing though. It’s the difference between firing something to 2200°, where the clay body is vitrified and very hard – this is called stoneware, or high fire pottery – and low fire earthenware, where it is only fired to 1800°, the clay body is still porous, but you can decoratively paint. High fire stoneware is what you see most art shows. It is where the piece has been dipped in a glaze and whatever happens, happens. Here at DIYC, what we mainly do is low fire earthenware, which is the clay body that best accepts decorative painting.

But that’s not to say that we can’t get a high fire stoneware look on our low fire earthenware clay pottery. It just requires using special glazes, and being willing to not know exactly what it’s going to look like what it turns out. It’s like wrapping your own present!

All glazes begin with raw elements and they change in the kiln. Pottery glazes really change in the kiln. Like…. A lot!

One thing about pottery glazes is that they CANNOT be dipped in another clear glaze. You must paint three really good coats of a color to make it look how you want it to look. And a “coat” means that you paint and let it dry until it has lost its shine, and then you are ready for your next coat.

These glazes have the most amazing ability to be combined. You can layer and add something called “magic flow”. Different things, including the shape of the pottery you are painting, affects what the glazes will do.

We have these glazes sampled in a number of ways in the shop – on the owls you can see how each color reacts to the texture, having high points and low points to show the color changes. Across each middle is a swipe of the magic flow. Each color reacts differently.
The small bowls are each painted in the same way, and you can tell how the different pottery glazes react differently. In the insides of all, we have 3 coats of the glaze, with a black line to show you how the glaze reacts with black paint. Some colors have a rusty look, some colors stay more black. It’s so cool! One the outside, we painted one side with two coats of black and then painted three coats of pottery glaze on top. On the other side, we painted three coats of pottery glazes. Some colors really show a difference – others not so much.

Layering different glazes gives you so many possibilities of reactions. It’s like picking drink flavors at Sonic!

Some people refer to pottery glazes as “art in a jar” because you get such amazing results. This is really true – you can paint an item with pottery glazes and be guaranteed with a wonderful finished piece.