Did you know we make all of our own glazes from scratch at Slowfire?
Alice and Noelle work together to develop all of the glazes that are available to students in the studios! We formulate and test many, many glazes to find the right colors, finish, and compatibility with our clays. The process starts with a recipe and we run many variables through our computer program. We also need to source all of the ingredients, which is fairly expensive as some of our ingredients are mined in England and India. We use a variety of materials for colorants, such as iron, rutile, copper and cobalt but we also purchase mason stains and inclusion stains for some colors, such as red.
Alice loves to find the best color palette and she is often very hard at work during the day in the glaze lab. She creates 100gram tests, make test tiles, and fires them in the kiln. Right now, we are working on finding the best orange and best brown for Cone 04 glazes. It is not a simple or quick process but it is so worthwhile to get the best color and finish (glossy, matte, satin).
Once we have determined the right percentages of ingredients (it is a lot like cooking but heavy on the chemistry), we mix up large 10,000g batches and weigh out each ingredient on the gram scale. You have to wear protective gear to work in the glaze lab, fyi. It is messy and dusty. The glazes get sieved and mixed and then we make even more test tiles to ensure our large 5 gallon buckets are perfect.
This is just a general overview of the process but check out our images below for some behind the scenes pictures of our glaze processing for pottery!