Glaze making // my choices explained
Making glaze for ceramics is not an easy job, it’s massively time consuming and basically you need to be a scientist to understand what you are doing.
However if you don’t make your own glazes from scratch you will never know exactly what’s in them. Commercial glazes are beautiful, food safe and easy to use but you cant access the recipes or find out what the raw ingredients are. Sadly that means you have no idea firstly what you could be absorbing into your skin but also where the raw ingredients come from.
I chose to make my own glazes to fully understand what I’m working with, to consider how that’s affecting the planet and also to provide transparently to those that buy my pottery.
Through years of research and asking questions as a continuous part of my work, I have learnt a lot about mining, raw ingredients and what’s best to avoid when trying to make sustainable choices.
I first create what is called a base recipe which consists of 3 to 10 raw ingredients which I weigh out, add water too, sieve, and then repeat until smooth like a cream. Every batch needs testing and then re-testing to ensure it is the right consistency to achieve the desired finish but that’s not even the complicated bit.
So these base recipes consist of different raw materials that are mined across the globe to varying standards to be used for a range of products.
The environmental impact of mining in particular countries is concerning for many reasons. Toxic pollution, corruption, use of children, risk of serious injury and death to the workers, acidic water pollution, coastal dredging and much more. Without a doubt this is cause for worry.
Predominately these destructive practices are reported to take place in countries such as Brazil, Canada, China, Australia, India and The Democratic Republic of Congo.
Children sorting cobalt ore in Kolwezi in the Democratic Republic of Congo © Amnesty International
There are so many reports out there to read about the dark side of mining and its really scary to think about. One particularly distressing aspect is the abuse of children in copper and cobalt artisanal mines in the southern Democratic Republic of Congo.
These children fall ill with various infections from working in polluted water or being exposed to mercury or uranium. Artisanal mining consists of digging, washing and sorting minerals all by hand. A shocking 40% of artisanal mining workers in the Democratic Republic of Congo are reported to be children as young as 3.
According to Tanya Talaga the Indigenous Issues Columnist, a Christian relief organisation called World Vision, interviewed 50 children working the mines. 19% told World Vision they had seen a child die while working, 87% felt severe body pain, 67% had a persistent cough and many of the girls had genital infections due to standing in waist-deep toxic water to work.
Mining minors: The pain of African child workers
So how do potters avoid this? Well many don’t even know about it and just buy ingredients from their local supplier without giving it a second thought. It is not information that is readily available and the information is not disclosed and rarely discussed.
There are clear international guidelines for responsible sourcing however like many others in todays world, some companies are not working within them and compromise human rights and the environment for the sake of profit.
Yes it is their responsibility to deliver clean and fair raw materials but I also believe as an individual maker, I must take responsibility for what goes into my pottery.
Understanding where my materials come from and asking about the supply chain as a consumer is something I value as part of my process. To make a consciously more sustainable glaze I have created recipes using my most local ingredients and purposefully avoid ingredients I don’t trust. It is carbon foot print and the ethical standards of mining that dictate my choices.
I predominantly use British mined ingredients to make my signature glaze recipes, a shinny clear and a chalky white. I contact the provider and confirm how they are produced, what ingredients are in them and where that comes from.
It can be really hard to identify what to avoid. So I thought it would be helpful to end this post by listing a few of my fav ingredients and where they are minded, followed by a couple of things I avoid and why:
Some glaze ingredients I love:
Hyplas Ball Clay - mined in Devon
Grolleg China Clay - mined in Cornwall
Dolomite - mined in Derbyshire
Whiting - mined in Derbyshire
Soda Feldspar- Norwegian sourced
Some glaze ingredients I avoid:
TALC- the illegal mining of talc in Afghanistan is funding insurgent activity by Islamic State and the Taliban. 80% of which is ending up in the USA and Europe.
SODA ASH- produced via an environmentally harmful industrial process called the Solvay process.
BONE ASH- made from the bones of cattle farmed animals. Not only harmful to the animals themselves but the CO2 emissions involved in livestock farming is a massive environmental problem that I do not want to contribute to as part of my work.
COBOLT-. The Democratic Republic of Congo currently produces more than 80% of the world's cobalt and involves child abuse to name just one of its issues. I cant avoid it being used in my mobile phone but I don’t need it in my pottery! Sometimes we cant avoid the evils, but when we can I believe we should make the kind choice. x
