Article written for South Wales Potters Newsletter ‘Shards’ issue Spring 2026

RECIPE FOR GLAZING

I first studied ceramics in the early 1990’s at Cardiff School of Art and Design before heading off to pursue a career as a hair and make-up artist in the film and television industry. When I eventually returned to clay, it was glazing that drew me in the most strongly.

For me, glaze is not an afterthought. It needs to be considered long before a form is conceived, so that clay and glaze can work together in a way that feels intentional and coherent. What follows is a snapshot of my glazing process as it currently stands. A working recipe, still evolving.

A GLAZE RECIPE FOR CERAMICISTS

Serves : Glaze enthusiasts

Ingredients

  • Aspirations for success

  • Plenty of curiosity

  • An interest in ceramic history

  • Knowledge of chemical materials

  • A place to document results

  • An appropriate kiln

Method

  1. Begin with testing. Small test tiles are invaluable, but it’s also important to test at your working scale.

  2. Create forms that complement the character and behaviour of the chosen glaze.

  3. Consider different methods of application to achieve desired outcomes.

  4. Apply heat using appropriate temperature and speed.

  5. Leave to cool in the kiln.

  6. Remove from kiln and serve with new ideas.

Over the past few years, I’ve worked with three different clay bodies, making deliberate choices about style and relationship between clay and glaze. For each clay and making technique, I’ve developed corresponding glazes.

  • Carved textured slip cast porcelain with tinted translucent glaze to highlight details.

  • Thrown and faceted low iron stoneware clay with calcium/magnesium crystalline glazes that breaks on edges.

  • Smoothly thrown off-white stoneware clay with zinc silicate glaze, encouraging the growth of abundant crystals, focusing on colour and pattern.

My glazing practice has been shaped by long hours of testing. Much of my learning has come through what might be described as ‘failures’, from which a successful process is refined. I’m currently working with zinc silicate glazes, which have proven to be a generous teacher. They clearly demonstrate how subtle changes in a recipe can lead to a very specific outcomes, deepening my understanding of how chemistry influences colour, surface and fluidity.

To start your own glaze testing journey, Glazy is a great resource. A library of glaze recipes that cover a multitude of styles, atmospheres and temperatures. For those drawn to these subtleties, I hope the hours at the glaze bench brings you discovery and joy. If you’d like to see more of my work taking shape, please look on instagram, @suthompsonceramics or explore this wbsite further.

Latest discovery from my making practice: The broken up crystalline glaze on the inside edge of this bowl has happened because of flashing from chrome that is present in the outside glaze of this bowl.