Lesson 1: The Science of Surface (Intro to Glazing)

Why does the color of raw glaze in the jar look different from the finished fired result?

How does the thickness of the glaze application affect the final texture and transparency?

What is the chemical purpose of the "wax resist" on the bottom of a pot?

Glaze: A layer of glass-forming minerals fused to the surface of a ceramic body through heat.

Bisqueware: Clay that has been fired once and is ready for glaze.

Crawl: A glaze defect where the glaze pulls away from the surface, often caused by dust or oil on the bisque.

Fit: The relationship between the expansion/contraction of the clay body and the glaze.

Kiln Wash: A refractory coating applied to kiln shelves to prevent sticking.

VA:Cr2.1.HS1: Demonstrate through knowledge and usage of specialty tools and equipment (brushes, tongs, wax) the safe and effective application of materials.

VA:Re9.1.HS1: Establish relevant criteria in order to evaluate a work of art or collection of works.

Chemical Transitions: Understanding how heat changes the state of matter (solid to liquid to glass), which is a core concept in physical science sections.

Predictive Reasoning: Using a "Glaze Test Tile" to predict outcomes, similar to using data sets to draw conclusions.

Description: Students will prepare their bisque-ware by sponging off dust, applying wax resist to the bottom, and layering 2–3 coats of glaze. They will learn to read "Glaze Charts" to choose compatible colors.

Purpose: To understand the functional and aesthetic finishing process of ceramics.

DOK Level: Level 2 (Skills and Concepts). Students must follow a specific technical protocol to ensure the safety of the kiln and the success of the finish.

Food Safety: Discuss why certain glazes (lead-free) are required for eating surfaces, connecting to FDA regulations.

Historical Alchemy: Explore how ancient civilizations (Egypt, China) discovered glaze by observing how wood ash reacted with clay in high-heat fires.

"More is better": Students often apply glaze too thick, which causes it to "run" off the pot and ruin the kiln shelf. I will demonstrate the "ideal thickness" (like a dime).

Glazing the bottom: Beginners often forget that glaze is essentially melted glass. I will enforce the "Dry Foot" rule: no glaze on the bottom 1/4 inch of the piece.

For Striving Learners: Use "Underglazes" which do not move or run, allowing for more predictable results similar to painting with tempera.

For Advanced Learners: Introduce "Overlapping"—layering two different glazes to see how they chemically react to create a third, unique color.

Visual: Create a "Glaze Library" of fired tiles so students can see the actual results of the jars.

• Critique participation / Sketchbook

• Reflection worksheet / Test Tiles

• Final project rubric

• Formative: The "Pinky Test"—Checking the thickness of the dry glaze before it goes into the kiln.

• Summative: Rubric focusing on:

  1. Application: Is the glaze even, or are there "bald spots"?

  2. Safety: Is the bottom of the pot perfectly clean of glaze?

  3. Intent: Did the student choose colors that enhance the form of the pot?

• Materials: Bisque-fired projects, assorted liquid glazes, soft mop brushes, wax resist, sponges, dipping tongs, and buckets of water.

• Resources: Glaze manufacturer color charts (Amaco/Mayco).

• Safety: Ventilated area for glazing; masks if using powdered glazes.