Ceramic Notes

Some of our earliest childhood memories begin the same way. Hands in earth, shaping mud cakes and messy creations. The smell of wet soil. The grit beneath the nails. The quiet satisfaction of forming something, watching it collapse, and trying again. 

As a child, mine certainly did.

Years later, I watched my son do the same. Hands deep in dirt, and yes, play dough too, building without instruction, absorbed entirely in the tactile sensation. More recently, we stood side by side at a potter’s wheel, clay spinning beneath our palms, form rising and falling in response to pressure. One foot kept the wheel turning while our hands shaped the clay, watching how a simple clump of clay could be contoured with each subtle movement.

There is nothing more grounding than touching earth.

Composing, whether a sketch, a stanza, or a vessel, draws from something deeply personal. Each piece developed through covellite carries the imprint of lived experience. That instinct led the studio into a deeper exploration of materials, beginning with ceramics and the quiet decisions that shape them.

In the world of ceramics, there are distinct types, each with its own history, chemistry, and temperament. Across time, clay has taken many forms. What gives earthenware its ancient charm? How does stoneware balance strength with simplicity? What makes porcelain so refined it has been treasured for centuries?

At some point in this process, I realised I was using the word ceramic without really questioning it.

Ceramic is often spoken about as though it is a single material. But it is a family. Clay-based bodies sit within it, yes, but so do bricks, tiles, sanitaryware, and engineered materials hardened by heat. What unites them is not appearance but process. Shaped, dried, fired, stabilised by heat.

In homeware design, when we say ceramic, it usually means clay that has been formed and fired to durability. But even within that narrower scope, there is remarkable variation in composition, absorption, strength, and behaviour.

And that variation is where design decisions begin.

While my understanding of the ceramic family expanded over time, our material development remained focused on two carefully selected compositions. Over several years, I worked closely with skilled craftsmen, evaluating each trial to understand how the compositions responded to pressure, heat, and repetition. Through repeated firing and adjustment, the material guided the evolution of form.

Clay does not leave the kiln the same size it entered. Depending on the composition, shrinkage can range roughly between five and fifteen percent from wet clay to final firing. A millimetre in a sketch can shift or disappear. When a piece must align with other components in a collection, those percentages matter. It taught me how unforgiving ceramics can be.

Vitrification plays its part. As firing temperatures rise, minerals within the clay begin to melt and bond more completely, a nuance I only later came to understand. The body becomes denser and less porous. Earthenware tends to retain higher absorption, while well-vitrified stoneware or porcelain reduce it significantly, often to just one or two percent. Absorption influences longevity, staining resistance, and performance in moisture-rich environments.

Thermal behaviour must also be considered. Mineral composition determines how a body expands and contracts with temperature change. Even glaze fit matters. Mismatched expansion rates between glaze and clay can lead to several issues such as cracking over time.

Clay shrinks. Particles fuse. Surfaces tighten. These are not minor technicalities. They determine durability, structural alignment, and lifespan.

And yet, when we encounter ceramics in the world, we rarely encounter that depth. We accept labels. Ceramic. Stoneware. Porcelain. Bone China. Dolomite.

For the non-potter, these words blur together. They appear on packaging, in product descriptions, stamped beneath vessels. But what do they truly mean?

What gives earthenware its ancient charm?

Earthenware is among the earliest ceramic bodies shaped by human hands. Fired at comparatively lower temperatures, it does not fully vitrify. The clay particles partially fuse, leaving the body more porous unless sealed with glaze.

Its softness and warmth are part of its character. It feels close to soil, immediate and grounded. Long before firing curves were mapped, it carried water and food. What we now measure was once understood through repetition and touch.

How does stoneware balance strength with simplicity?

By increasing the firing temperature, the structure shifts. Minerals assist vitrification, bonding particles more completely and reducing porosity. Stoneware becomes denser, stronger, and more resistant to moisture penetration and wear.

It tolerates repetition and temperature change with greater reliability. Heat alters structure at a microscopic level. Integrity increases as internal voids decrease.

Durability, in ceramic terms, is often a measure of vitrification.

What makes porcelain so refined it has been treasured for centuries?

Traditional hard-paste porcelain, first perfected in China, is composed primarily of kaolin and feldspathic stone. It is entirely mineral-based. Fired at significantly higher temperatures, it achieves extensive vitrification and very low absorption.

When thin, porcelain becomes translucent due to its tightly fused structure and minimal impurities. Its refinement is structural as much as visual. It possesses high compressive strength, though its lower plasticity during forming demands precision.

How can something feel delicate and still be strong?

Bone china emerged in eighteenth-century England as an adaptation of porcelain. Unlike traditional Chinese porcelain, which relied solely on mineral composition, bone china incorporates bone ash into the clay body. Produced by calcining animal bone into a fine, calcium-rich powder, the addition increases translucency while enhancing fired strength. It alters how the material vitrifies, creating a denser internal structure that allows pieces to be formed thinner without compromising integrity.

Base clay is only the beginning

What we call ceramic is rarely clay alone. A ceramic body begins with a base, earthenware, stoneware, or porcelain, and is often modified.

Grog, pre-fired and crushed ceramic particles, may be added to reduce shrinkage and improve structural stability. Feldspar acts as a flux, assisting vitrification. Minerals such as dolomite may be introduced into clay bodies or glazes to influence surface character and firing response.

Dolomite functions primarily as a modifier rather than a primary clay source. The name on the box is rarely the full story. The kiln reveals more.

As ceramic production evolved, clay bodies became more consistent. Mineral ratios refined. Firing schedules standardised. Ceramic moved from purely artisanal to precisely engineered.

Today, when we hold a ceramic object, we hold centuries of experimentation in our hands. Earth shaped by both tradition and innovation.

As the form evolved, material became the measure of endurance.

What will this endure?
How will it age?
How will it respond to water, humidity, repeated touch?
How will shrinkage affect alignment within a complete system?

Over years of research and development, the two ceramic materials we selected were fired and refined again and again. Some iterations held the form beautifully. Others revealed their limits. Every firing taught us something.

Just as in childhood, rebuilding clay forms beside my son reminded me that the lesson was responsiveness. 

Material is never neutral. It shapes how a piece lives in use as much as its design.