The Final Bake: Glaze Firing · Oxidation vs. Reduction

Medium

Fire test tiles in oxidation

Before you can understand the difference between oxidation and reduction, you need a baseline. Electric kilns fire in oxidation (full oxygen atmosphere), which is your starting point.

The exercise

  1. Glaze six test tiles with different glazes from your studio
  2. Fire them in a standard electric (oxidation) kiln to your target cone
  3. After firing, document each tile:
    • Color (photograph in natural light)
    • Surface texture (glossy, matte, satin?)
    • Any defects (pinholing, crawling, etc.)

Build your reference set

Label each tile with:

  • Glaze name/recipe
  • Cone fired to
  • "Oxidation"
  • Date

These become your permanent oxidation reference. When you later fire the same glazes in reduction, you'll have a direct comparison.