8.5: Making and Using Glaze Test Tiles
- Page ID
- 299312
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Designing Test Tiles That Effectively Display Glaze Characteristics
- Shape and Size: Use tiles with a flat area for color and texture tests, as well as vertical sections to observe how the glaze flows.
- Consistency: Create test tiles from the same clay body as your final pieces to ensure accurate results.
- Marking: Label each tile with a reference number, recipe, or glaze name for clear identification after firing.
- Adaptability: Include details like ridges, incised lines, or carved textures to observe how the glaze interacts with different surface features.
Systematic Approaches to Applying Glazes on Test Tiles
- Single Glaze Testing: Apply a uniform coat of a single glaze to observe its base properties, such as color, opacity, and texture.
- Layered Applications: Test combinations of multiple glazes to observe interactions. For example, apply a base coat of one glaze and a second glaze over part of the tile.
- Variable Thickness: Apply the glaze in gradients, from thin to thick, to study how variations in application affect the result.
- Controlled Firing: Fire all test tiles in the same kiln load to ensure consistent conditions and reliable comparisons.
Organizing and Conducting Glaze Firing for Test Tiles
- Batch Testing: Group similar tests (e.g., variations of the same glaze) in the same firing for easier analysis.
- Kiln Placement: Place test tiles in different areas of the kiln to study the impact of temperature variation. For example, tiles near the kiln's top may experience higher heat.
- Firing Records: Document the firing schedule, including temperature ramps and holds, to replicate or adjust conditions in future tests.
- Post-Firing Notes: Record observations immediately after unloading the kiln, noting any unexpected effects or anomalies.
Analyzing and Interpreting Test Tile Results
- Surface Quality: Examine the glaze for smoothness, texture, and flow. Identify areas where the glaze ran, pooled, or cracked.
- Color Variations: Compare color intensity, richness, and evenness across tiles. Note how thickness or overlaps affect the final hue.
- Functional Qualities: Test for durability, adhesion, and food safety (if applicable). For example, a glossy glaze on a mug rim should be smooth and non-porous.
- Refinement: Use the best-performing tests as the basis for further recipe adjustments or as final glaze formulas.
Creating a Reference Library of Glaze Test Tiles
- Organized Storage: Store test tiles in labeled boxes or on display boards, sorted by firing temperature, clay body, or glaze type.
- Comprehensive Notes: Attach written notes or digital records to each tile, including the recipe, firing conditions, and application method.
- Visual Comparisons: Display tiles in a way that allows quick comparisons, such as grouping them by color or finish.
- Ongoing Documentation: Continuously update your library with new tests to build a robust resource for future projects.