Ceramic glazes are used to decorate pottery in different ways. Layers of glaze are also key in sealing, waterproofing, and strengthening ceramics, making pieces like mugs and plates food-safe.
This Basics of Ceramic Glazing video from Clay Corner Studio expertly demonstrates different types of ceramic glazes and application techniques. Introductory best practices are also reviewed, including making numbered test tiles to catalog glazes.
More about glaze chemistry by artist Olivia Aspegren:
“All glazes contain three primary components: a glass former to create the glassy surface, a flux to lower the melting point, and a stabilizer to make sure the glaze doesn’t just melt off the clay object…
“Silica, the short name for silicon dioxide (SiO2), is by far the most common glass former…
“The most common fluxes are sodium, potassium, calcium, and barium, all alkali metals. Sodium oxide, when mixed with water, becomes sodium hydroxide (NaOH). When sodium oxide reacts with silica, it breaks up the silica network, making it easier to melt it down — acting as a flux…
“Stabilizers stiffen molten silica, making a glaze more viscous. Alumina, titanium oxide, and zirconium oxide are common stabilizers. Alumina has a structure that is close-packed and almost hexagonal, a which acts as a good stabilizer.”
Watch these related videos next:
• How to throw, trim, and glaze a bud vase, narrated by Florian Gadsby
• Repairing a Meissen Lion + King Augustus the Strong’s Menagerie
• The art of carving with Haruya Abe
• Ceramic artist Michelle Erickson recreates an 18th-century agateware teapot