The Real Reason I Fire to Cone 10
Cone 6 is easier on the kiln, the elements and the schedule. I fire to cone 10 anyway, and the reason is simple: how the glazes look.
I fire to cone 10 because of depth. Cone 6 glazes can be bright, clean and reliable, but they tend to sit on top of the clay. At cone 10, iron breaks warmer, celadons gain depth, ash glazes layer, and the glaze feels absorbed into the body instead of applied.
- Cone 6: efficient, practical, easier on electric kilns, endless glaze options
- Cone 10: harder on elements and slower, but surfaces mature inside the glass
- Salt firing lives in the cone 10 range, so high fire is where my work is headed
There are easier temperatures to fire to. Cone 6 is efficient and practical. It is easier on an electric kiln, the elements last longer, firings are shorter, and there are endless glaze options designed for it. If I wanted to simplify my life, I would stop there. I do not. And the real reason has nothing to do with being stubborn or traditional. It is how cone 10 glazes look.
The first side by side
The first time I compared a cone 6 glaze to a cone 10 glaze side by side, I did not have the language for it yet. I just knew one felt deeper. Cone 6 surfaces often sit on top of the clay. They can be bright, clean and consistent. They do what they are supposed to do, the color shows up as advertised, and the finish is reliable.
Cone 10 glazes move differently. At higher temperatures, everything slows down and sinks in. Iron breaks warmer. Celadons gain depth instead of brightness. Surfaces develop variation inside the glass instead of just on it. The glaze does not just melt. It matures.
Applied versus absorbed
There is a softness to cone 10 surfaces that is hard to fake. Not dull, just integrated. The surface and the clay body feel like they belong to each other. At cone 6, a glaze can feel applied. At cone 10, it feels absorbed. I have opened cone 6 firings and thought, that worked. I have opened cone 10 firings and thought, that is alive.
Where you see it most
The difference shows up most in earth tones, the kind I am drawn to. Iron reds at cone 6 can look bright and sharp. At cone 10, they deepen. Browns feel more grounded. Ash glazes develop layers instead of a flat coat. Even clear glazes feel different: less glossy, more settled. There is more heat work happening, more movement inside the melt, more conversation between clay and glass. That is what keeps pulling me higher.
The cost, and why I pay it
It is not that cone 6 is wrong. It just does not produce the surfaces I am chasing. If I am building toward salt fired pottery and a salt kiln of my own, the high fire world is where those surfaces live. Salt firing happens in that cone 10 range. The warmth, the flashing and the density all depend on that level of heat.
Cone 10 is harder on my electric kiln. I see it in element wear and longer firing times, and I feel it in maintenance. But when I pull a mug from a fully matured cone 10 firing and the glaze feels deep instead of shiny, integrated instead of coated, I remember why I keep pushing it.
The real reason I fire to cone 10 is not tradition. It is depth: the way the glaze settles into the clay instead of sitting on top of it, and the way high fire ceramics carry quiet complexity instead of loud color. Once you see that difference, it is hard to unsee.
If you want to see the difference yourself, find one glaze sold in both a cone 6 and a cone 10 version and fire a tile of each on the same clay. Hold them side by side in daylight. The cone 10 tile usually looks like the color is inside the surface, not painted on it.
Still chasing depth over brightness and letting the kiln decide the rest.
