All Articles A Low Cost Tester of Glaze Melt Fluidity A One-speed Lab or Studio Slurry Mixer A Textbook Cone 6 Matte Glaze With Problems Adjusting Glaze Expansion by Calculation to Solve Shivering Alberta Slip, 20 Years of Substitution for Albany Slip An Overview of Ceramic Stains Are You in Control of Your Production Process? Are Your Glazes Food Safe or are They Leachable? Attack on Glass: Corrosion Attack Mechanisms Ball Milling Glazes, Bodies, Engobes Binders for Ceramic Bodies Bringing Out the Big Guns in Craze Control: MgO (G1215U) Ceramic Glazes Today Ceramic Material Nomenclature Ceramic Tile Clay Body Formulation Changing Our View of Glazes Chemistry vs. Matrix Blending to Create Glazes from Native Materials Concentrate on One Good Glaze Cone 6 Floating Blue Glaze Recipe Copper Red Glazes Crazing and Bacteria: Is There a Hazard? Crazing in Stoneware Glazes: Treating the Causes, Not the Symptoms Creating a Non-Glaze Ceramic Slip or Engobe Creating Your Own Budget Glaze Crystal Glazes: Understanding the Process and Materials Deflocculants: A Detailed Overview Demonstrating Glaze Fit Issues to Students Diagnosing a Casting Problem at a Sanitaryware Plant Drying Ceramics Without Cracks Duplicating Albany Slip Duplicating AP Green Fireclay Electric Hobby Kilns: What You Need to Know Fighting the Glaze Dragon Firing Clay Test Bars Firing: What Happens to Ceramic Ware in a Firing Kiln First You See It Then You Don't: Raku Glaze Stability Fixing a glaze that does not stay in suspension Formulating a Clear Glaze Compatible with Chrome-Tin Stains Formulating a Porcelain Formulating Ash and Native-Material Glazes Formulating Your Own Clay Body G1214M Cone 5-7 20x5 Glossy Base Glaze G1214W Cone 6 Transparent Base Glaze G1214Z Cone 6 Matte Base Glaze G1916M Cone 06-04 Base Glaze G1947U/G2571A Cone 10/10R Base Matte/Glossy Glazes Getting the Glaze Color You Want: Working With Stains Glaze and Body Pigments and Stains in the Ceramic Tile Industry Glaze Chemistry Basics - Formula, Analysis, Mole%, Unity, LOI Glaze chemistry using a frit of approximate analysis Glaze Recipes: Formulate Your Own Instead Glaze Types, Formulation and Application in the Tile Industry Having Your Glaze Tested for Toxic Metal Release High Gloss Glazes How a Material Chemical Analysis is Done How desktop INSIGHT Deals With Unity, LOI and Formula Weight How to Find and Test Your Own Native Clays How to Liner-Glaze a Mug I've Always Done It This Way! Inkjet Decoration of Ceramic Tiles Is Your Fired Ware Safe? Leaching Cone 6 Glaze Case Study Limit Formulas and Target Formulas Low Budget Testing of the Raw and Fired Properties of a Glaze Low Fire White Talc Casting Body Recipe Make Your Own Ball Mill Stand Making Glaze Testing Cones Monoporosa or Single Fired Wall Tiles Organic Matter in Clays: Detailed Overview Outdoor Weather Resistant Ceramics Overview of Paper Clay Painting Glazes Rather Than Dipping or Spraying Particle Size Distribution of Ceramic Powders Porcelain Tile, Vitrified or Granito Tile Rationalizing Conflicting Opinions About Plasticity Ravenscrag Slip is Born Recylcing Scrap Clay Reducing the Firing Temperature of a Glaze From Cone 10 to 6 Single Fire Glazing Soluble Salts in Minerals: Detailed Overview Some Keys to Dealing With Firing Cracks Stoneware Casting Body Recipes Substituting Cornwall Stone Super-Refined Terra Sigillata The Chemistry, Physics and Manufacturing of Glaze Frits The Effect of Glaze Fit on Fired Ware Strength The Four Levels on Which to View Ceramic Glazes The Majolica Earthenware Process The Physics of Clay Bodies The Potter's Prayer The Right Chemistry for a Cone 6 MgO Matte The Trials of Being the Only Technical Person in the Club The Whining Stops Here: A Realistic Look at Clay Bodies Those Unlabelled Bags and Buckets Tiles and Mosaics for Potters Toxicity of Firebricks Used in Ovens Trafficking in Glaze Recipes Understanding Ceramic Materials Understanding Ceramic Oxides Understanding Glaze Slurry Properties Understanding the Deflocculation Process in Slip Casting Understanding the Terra Cotta Slip Casting Recipes In North America Understanding Thermal Expansion in Ceramic Glazes Unwanted Crystallization in a Cone 6 Glaze Variegating Glazes Volcanic Ash What Determines a Glaze's Firing Temperature? What is a Mole, Checking Out the Mole What is the Glaze Dragon? Where Do I Start? Why Textbook Glazes Are So Difficult Making Glaze Testing Cones
A standard shape and size of glaze test is important to be able to compare one test with another, especially over time (so that old tests look the same as new ones)
Joe Schmidt, lab technician at
Plainsman Clays, developed the glaze testing cone, it is very practical. It is a standard shape and size that is always used, this serves well for comparison and documentation purposes.
They are easy to make.
They are easy to photograph
They are stable and less likely to tip over and break
They stack well in boxes
They display a glaze in a way that is akin to a piece of pottery or
Steps to make these:
Print the pattern and cut it out
clay to 1/4 inch (6mm) thickness Cut the shape out of the clay using the pattern
Apply a band of slip to one end and attach the other using a 15mm (1/2 inch overlap)
Press the joint firmly together (use a stick on the inside to support) and press the indentations
Dry the clay to leather hardness and carve a design on the side opposite the join (to show what it does on edges, in varying thickness around contours and on an uneven surface)
Stamp the identification of the clay at the bottom
Dry the testers carefully to avoid cracking
Use a knife to trim off any sharp edges
When dipping these in glaze consider the following:
Dip down to within 15mm (1/2 inch) of the base
Label clearly on the bare clay section
Dip the top half again for a double-thickness.
Use the link below to download the pattern file.
An example of the value of a good glaze testing sample.
These are made at
Plainsman Clays in Alberta, Canada.
Preparing to make a glaze testing cone: cutting around the pattern
In this picture a piece of cardboard is used as a template, you can download a pattern using the URL link on this page.
Making a glaze testing cone: applying the slip for the join.
A viscous slip will make a better join and minimize the chance of water-splits developing at the edge of the overlap.
Making a glaze testing cone: finishing the join.
With most clays no scoring is needed, the slip and pressure are enough to make a good join.
Making a glaze testing cone: Incising the surface
Glaze thickness thins on the edges of the incised lines and thickens at their bases. This enables variegating glazes to showcase their visual effect with varying thickness. And these test the ability of opaque glazes to still cover well when the layer is thin.
Making a glaze testing cone: Stamping an identification.
The code numbers get recorded with the pictures in our testing system (an account at