The Art of Glaze Chemistry
You can develop and adjust your own glaze recipes, even if it seems complicated right now
Do you ever feel stuck, frustrated, and at the mercy of disappointing glaze results (or the so-called "kiln gods”)? Maybe your glazes run, craze, or turn out dull no matter how much you tweak them.
You have relied on advice from others, unsure if it will actually help. You’re tired of experimenting endlessly, only to end up back where you started.
But what if you could understand exactly why your glazes behave the way they do—and know how to adjust them yourself, with confidence?
With The Art of Glaze Chemistry, you'll go from feeling overwhelmed and uncertain whether glaze chemistry is something you will be able to understand, to creating stunning, reliable, and unique glazes with greater control and consistency.
No more wasted firings. No more blind trial and error. Just clear, science-based techniques and processes that give you full creative control over your glazes.
You just need to learn The Art of Glaze Chemistry
A lot of students come to me after they’ve been glazing for some time. They've had some ‘ok’ results but wish they were better. They haven’t been able to create the glazes they really want to put on their pots.
They know they want to understand glazes on a deeper level, but they are intimidated by the thought of learning glaze chemistry. They think it will be too complicated and they aren’t sure if they’re up to the challenge.
When I show them the way that I teach glaze chemistry, coming from the perspective of both an artist and a scientist, bringing those two amazing concepts together, here's what becomes possible.
Potters who perceive glaze chemistry as a very difficult, insurmountable side of the glazing process start to see themselves as capable of creating the glaze recipes they have imagined, regardless of how complicated it appeared or felt in the beginning.
Here's what past AGC students are saying:
“The course is very well structured, Sue is an excellent teacher that is able to clarify, with a lot of patience, the chemistry of glazing, even to complete chemistry novices.
By the end you will feel empowered to make changes to your existing glazes, and perhaps make up your own!“
“I was hesitant — partly because chemistry is just intimidating, but also because of the time and expense involved! That said, my only regret is not doing it sooner!
Sue is a fantastic teacher. She has a way of making complex topics easily digestible, and she is incredibly generous with her knowledge!
In addition, I really appreciate the way the class is structured for maximum flexibility. I highly recommend this course to all my pottery friends!!”
“I learned how little I really knew about the proper chemistry of durable glazes. I've been mixing glazes for over 20 years, apparently by the seat of my pants and a lot of luck!
It is an amazingly eye-opening course and every serious glaze mixing potter should know the chemistry involved in successfully mixing their glazes.”
By the end of this course, you'll be able to:
🤓 Fix your runny glaze
🤓 Fix your crazing glaze
🤓 Adjust recipes when materials are no longer available
🤓 Ensure your glazes are durable and suitable for food surfaces
🤓 Use glaze calculation software to predict glaze behaviour
🤓 Create your own unique glaze recipes
These are just some of the topics we cover in the Art of Glaze Chemistry!
The science class that was made for ceramic artists
You probably didn't take your first pottery class thinking you'd need to take a science class to become really good at it. But the fact is, that the chemistry is happening in the kiln, whether you understand it or not.
Why not empower yourself by learning the science that will help you to become a better potter.
The Art of Glaze Chemistry will teach you about:
⚛️ The composition of glazes so you can look at recipes and identify why each material is included in the glaze, as well as suitable substitutions for materials you don't have access to.
⚛️ Glaze melting temperatures and how to adjust them so you can make your glazes more or less fluid, depending on your aesthetic goals or problems you're trying to solve.
⚛️ What makes glazes matte, glossy or satin, and how you can change the surface of any glaze recipe to suit your pots
⚛️ What makes glazes durable so you can avoid using glazes that might not be suitable for food surfaces.
⚛️ How thermal expansion works so you can solve issues like crazing, shivering and dunting.
Using glaze chemistry to create and adjust glazes is not an exact science. There are subtleties and nuances and exceptions to almost every "rule" or pattern. This is why I called this class The Art of Glaze Chemistry.
It's as much art as it is science. There is an art to how you use the science to create your art!
The power of understanding glaze chemistry will take your pottery to the next level
Here's what past AGC students are saying:
"Thank you Sue for this amazing course! Glaze chemistry was an area that overwhelmed me before but from the first session, you made it approachable and fascinating; I felt relaxed and ready to explore more.
Your kindness in answering all our questions and the time you dedicated to organizing the course and preparing the handouts did not go unnoticed.
I have also enjoyed the Zoom meetings (even though they were very late in my time zone). Your enthusiasm was so infectious that kept me wide awake and engaged. Who needs coffee when you have Sue's energetic teaching to keep us going?
Add to this, it's been wonderful to connect with such a group of passionate potters from different parts of the world! Thank you Sue for all your hard work and dedication."
"Sue thank you for such an amazing class! I really appreciate how you broke down the steps to learning the chemistry of glazes. You covered so much information and I love that we could ask question after question.
I feel very confident in what I have learned and know I will use the information for the rest of my ceramics career."
"Sue, I wanted to take a moment to tell you how grateful I am for all the knowledge and time that you so generously share! I have taken all of your offered courses and have enrolled in The Glaze Lab community.
I have learned so much and have developed a level of confidence that will foster ongoing experimentation and learning.
If anyone is on the fence about taking one of your courses.... I say jump on in! You will be amazed by all that you learn!
Sue makes complex concepts easy to learn and her classes build on your knowledge. And an added bonus is the world community! Thanks so much!"
Join The Art of Glaze Chemistry
Here's everything included in The Art of Glaze Chemistry
- Lifetime access to The Art of Glaze Chemistry program - 8 Video Modules delivered over 10 weeks, that can be watched on your own schedule.
- Glaze testing assignments that will give you a tangible understanding of how glaze chemistry works
- Worksheets, action plans, presentation slides, video transcripts
- 8 weekly Q&A sessions with Sue on Zoom (see schedule) and lifetime access to Zoom recordings
- Private, students only community for asking questions 24/7 (not on Facebook)
- Glaze Resource library full of supplementary articles and videos to watch
- Glazy Bonus - 2 months free Glazy Patron status to unlock special features
- Glaze Materials Workshop Bonus - instant access to my "What Do the Glaze Materials Do?" masterclass
Payment Options – USD/CAD
Pay in Full – 1 payment
$597 USD / $795 CAD + tax
Payment plan - 3x monthly payments
3 x $210 USD / 3 x $275 CAD (+ tax)
= $630 USD total / $825 CAD total (+ tax)
Payment by PayPal or credit card.
You can choose monthly payment option on checkout page.
Early Bird Bonus:
Anyone who registers for The Art of Glaze Chemistry by midnight Pacific time, Mon, September 21 will also receive my 2-hour Firing Schedules/Kiln Programming workshop.
Learn to program and adjust your own firing schedules for the ultimate control over your glaze results.
Registration is open for:
Day(s)
:
Hour(s)
:
Minute(s)
:
Second(s)
Guarantee/Refund policy (click to expand)
I'm certain that you're going to learn so much in this course that you won't want to cancel. But if you need peace of mind, I'm offering a 14-day full money back guarantee (14 days from the release of Module 1) so you can complete the first 2 Modules and attend the first 2 Zoom Q&A sessions before deciding if it's the right next step for you.
Refund requests must be received by Sat, October 10, 2026 at 5pm Pacific time. This is technically a "no questions asked" refund policy, meaning your refund request won't be declined for any reason if requested by the deadline, but I will ask for feedback so I can understand why it wasn't a good fit.
Jump to section
Click icon to go straight to that section of the page.
Course Details
View course details
Schedule
View course schedule
Course Curriculum
View curriculum of the course
FAQs
View frequently asked questions
Testimonials
Love from my students
Register
Sign up for AGC
Course Details
Overview:
The Art of Glaze Chemistry is a 10-week guided program, complete with Sue's support in answering your questions on weekly Zoom calls and inside a private, student community.
Pre-requisite:
The one thing you need to know before taking this class is how to mix your own glazes from scratch. It will be assumed that all Art of Glaze Chemistry students already know how to do this and instructions won't be provided. If you'd like to learn how to mix your own glazes from scratch, consider taking my Glaze Mixing Essentials program.
Start Date:
The course officially starts on Sun, September 27, 2026 with the release of Module 1. Registration opens September 17 and you can get started with course prep as soon as you register.
Module Release:
Every Sunday you'll get access to a new Module. There are 8 Modules in total and we'll have 2 "Implementation weeks" throughout the course so you can get caught up on the lessons and glaze testing assignments if needed.
Lifetime Access:
Once modules are released, you have lifetime access so you can go back and review them as much as you like. "Lifetime access" refers to the lifetime of the program, for as long as I am offering this program. I have no plans to discontinue this program and I am often updating it as I learn new things. You will receive all program updates as well.
Weekly Zoom Q&A Sessions:
We'll have a 2-hour, live Q&A session over Zoom every Thursday at 10am Pacific / 1pm Eastern. The Zooms will be recorded and uploaded to your student dashboard.
Student Community:
There's a private, student community (not on Facebook) for discussions and sharing glaze results.
Glazy BONUS:
All new students will be offered 2 months of free "Patron status" on Glazy.org. We'll be using the glaze calculation software on Glazy.org throughout this course. Patron status unlocks special features on the site like:
- Target & Solve
- Blends
- Dark Mode
- Calculated Thermal Expansion
- Decimal Places
- Limits
After your 2 free months are up, you can continue your Patron status by donating $2/month to Glazy developer, Derek Au.
What Do the Glaze Materials Do? Masterclass BONUS:
When you register, you'll also get access to my intro to glaze materials class so you can start learning the basics of chemistry right away!
Course Schedule
Here's the schedule for the Fall 2026 session.
Are you ready to increase your knowledge and confidence with glazes?
Join The Art of Glaze Chemistry!
Registration is open for
Day(s)
:
Hour(s)
:
Minute(s)
:
Second(s)
Here's what past AGC students are saying:
"This class is good for someone who is ready to learn the why's of glaze instead of just copying recipes from the internet. You will learn how to analyze a glaze and change characteristics with Glazy. Not for the faint of heart, this is in-depth study of how a glaze is developed and altered."
"Sue takes a complicated subject and breaks it down into manageable pieces so it's easy to understand. She uses detailed chemistry in direct relation to mixing glazes so I could follow along and understand the 'why' behind the theory. The hands on experiments throughout the class, her instruction and feedback, helped me gain a better understanding as I applied the knowledge and gained confidence in mixing my own glazes."
"I have already been telling people about this class. I think it is really well put together and accessible to people at all levels. Sue is a great teacher and it is very obvious that she is excited about the material she is teaching. With materials constantly changing it is very helpful to feel empowered and understand how you can find ways to continue making the same or similar glazes you have been working with and or just make up new ones."
Who This Class is For:
This class is for potters/ceramic artists who have experience with glazing and already know how to mix their own glazes, but don't yet have a clue about the chemistry.
You'd be perfect for this class if you're familiar with the names of glaze materials but don't understand their function. Perhaps you've heard of feldspar but not sure what it's used for.
Maybe you've tested glazes with different colourants, but have never adapted the base recipe.
Maybe you've dabbled with some chemistry or material substitutions and you like to look at the UMF of your glazes but you're not quite sure what it all means.
You do need to know how to mix a glaze from a recipe, but you don't need any more knowledge than that.
If you want to learn how to mix glazes from scratch, consider taking my Glaze Mixing Essentials course first. Then you'll be ready for The Art of Glaze Chemistry.
Watch the AGC Curriculum Overview Video
AGC Curriculum outline:
Here's a list of the Modules that are released each week. Click on each one to read the topics covered in that Module.
Module 1: What is a Glaze?
- Intro to the periodic table and the main 11 elements we use in glaze chemistry
- Glass formers and fluxes and the purpose of each material in a glaze formula
- The issue with soluble materials in glazes
- Identifying why each material was added to a glaze recipe
Module 2: Chemistry and the UMF
- Why we need to learn glaze chemistry
- Atoms, molecules, and moles
- Chemical analyses of materials
- How to calculate the UMF of a glaze recipe
Module 3: The UMF and Durability
- The basics of temperature
- Comparing UMFs
- The importance of glaze durability for functional wares
- The difference between "Food Safety" and "Durability"
- Flux ratio and durability
- The role of B2O3 for durability at temps below cone 10
- The "Bristol" reaction - Zinc + Calcium = lower melting temp
Module 4: Silica, Alumina and the Stull Chart
- The Stull Chart - matte, glossy, underfired, crazing regions
- SiO2:Al2O3 ratio
- Properly formed matte glazes - "Stull" matte glazes
- Understanding low alumina levels
- Sue's Stull research at cone 6, 2 different flux ratios
- Adding Silica to a glaze
- The 5:1 matte line
- Stull shows you which direction to take to alter and fix glazes
Module 5: Glaze Formulation and Material Substitutions
- Analyzing the UMF of glaze recipes - what to look for
- Comparing to the UMF of known glazes
- Intro to glaze improvements
- What to pay attention to when substitution materials or formulating glazes from scratch
- The issues with soluble materials
- Oxide sourcing tips
- Theoretical formulas for materials
- Material substitution "Order of Operations"
- Which materials to avoid if possible
Module 6: Colourants and Opacifiers
- Where the colourants and opacifiers fall on the periodic table of elements
- Examples of how colourants and opacifiers turn out differently depending on the base glaze they're added to
- How colour response is affected by different variables like RO flux choice and silica/alumina levels
- Behind the scenes of colourant testing
- The difference between the 3 opacifiers - titanium, zirconium and tin
- How titanium is affected by cooling cycle
- How to convert from Copper oxide to Copper carbonate in a glaze recipe
Module 7: Adjusting and Improving Glazes
- Strategies for adjusting and improving your existing glaze recipes
- How to change from matte to glossy and vice versa
- How to change melting temp to fix runny or under-fired glazes
- Thermal expansion and how to fix crazing, shivering and dunting
- How to improve durability of your glazes
- Using volumetric blending to test multiple variations between 2 recipes with different colourants and/or different base glaze chemistry
Module 8: The Glaze Journey Continues
- Congratulations!! You made it to the end of this course, but this is not where the learning ends!
- Full course review of the main, important topics covered in each module
- A few bonus lessons added about:
- "Limits" - their significance and how to see them on the Glazy Stull chart
- Colourants as fluxes and the Extended UMF in Glazy
- Calculated expansion numbers in Glazy
- Words of encouragement from Sue about continuing on your Glaze Journey, learning at your own pace, embracing failures and sharing knowledge.
It’s a great time to learn The Art of Glaze Chemistry.
Registration is open for
Day(s)
:
Hour(s)
:
Minute(s)
:
Second(s)
Here's what past AGC students are saying:
"I had gotten to a point of avoiding glazing, because some things weren't working, and I didn't feel confident fixing them. Now I feel excited to play with any glazes that aren't working, and to test, test, test!
This course was a practical hands-on experience that gave me confidence to modify my glazes and develop new glazes that are uniquely my own. Sue explained the chemistry concepts in a way that was both in-depth, but also understandable to a non-scientist. The experiments were invaluable in helping to solidify the knowledge and helping me to overcome my fears of 'messing up.'"
"Sue McLeod's The Art of Glaze Chemistry, takes a complicated subject and breaks it down into simple steps. Having specific experiments for key ideas really gave me a visual understanding of how various components of a glaze work together. Make sure you have at lease 50 test tiles ready when the class starts, and 150 if your curiosity can get the better part of your glaze experiments!"
"Exceeded my expectations! I feel like I have a solid foundation on which to build, deepen, experiment, and think critically as well as creatively. I feel like the course was exceptionally well laid out and took us from the very basics to common complexities with clarity, humor, and no pretense. It felt like a safe place to ask questions and to learn from other questions.
AGC has enabled me to expand my creative and design ideas. By working through this course, I gained the necessary knowledge and confidence to keep learning! I can now make educated experiments using materials, tools, and online programs to bring my ideas to life."
Make Your Glaze Testing Efforts Count
Once you fully understand the concepts I teach you in this class, which will require some glaze testing homework, you'll be able to create, change and manipulate glaze recipes to get them working the way you want them to.
But it's not going to be one and done. You have to be willing to put in the work, test and fail and learn and test again. I can teach you hours and hours of glaze calculation theory, but the knowledge really comes when you make the tests and then open the kiln and see results for yourself.
It's like reading a book on how to ride a bike, versus getting on an actual bike.
The reason I have such a strong understanding of glazes is because I took classes to learn glaze chemistry and then I tested all the theories that I was learning to prove them to myself. It wasn't until I did extensive testing that I finally felt like I really understood enough to teach others.
You'll get out what you put into this class, but you don't have to rush. You can take your time and I'll be here to support you along the way. This 8 week class will just be the beginning.
Turn Glaze Confusion into Clarity and Understanding
It's really life changing when something that can cause so much grief and frustration like glazes finally becomes rewarding when you understand why they behave the way they do and have the knowledge to troubleshoot and solve problems as they arise.
And the best part is when you can develop your very own glaze recipes out of thin air. This is what's possible when you embrace and learn the art of glaze chemistry.
An example of the testing you'll be doing
When you take this class, I'll be giving you some glaze testing experiments to help you understand how chemistry is affecting your fired glaze results. Once a few of you have shared your results with the group, I'll make a video where I go through and analyze the chemistry of your glaze tests.
In this video, I go through the results of Barbara's Remove a Material and Subbing Fluxes Experiments (Fall 2021 student) and look at them through the lens of the UMF.
If this all sounds confusing to you, not to worry! By the time we get to this part of the class, you're going to understand everything I'm talking about.
Hopefully this will inspire you to want to understand how to look at glazes in this way.
Resource Library Included With the Program
You'll have access to an extensive, completely searchable Resource Library full of supplementary videos and articles that I reference throughout the course, for further learning of many topics related to glazes.
Here's a sample preview of some of the videos in the Resource Library.
Don’t wait for your next disappointing kiln opening.
Registration is open for
Day(s)
:
Hour(s)
:
Minute(s)
:
Second(s)
Frequently Asked Questions
How much studio work is assigned?
There will be glaze testing assignments throughout the course, in Modules 1, 2, 4 and 6. Expect to spend a few hours in the studio for each of these assignments. We’ll have an Implementation week (no new lessons) after Module 3 and Module 6 to allow time to complete these assignments. This way you can get your tests fired and get my feedback on your results before the end of our time together.
How long will I have access to the course for?
You'll have lifetime access to the program so you can come back and review the lessons as much as you like.
What if I can't attend the Zoom Q&A sessions?
You definitely DON'T need to attend the Zoom calls live in order to get my support in this program. I'll answer your questions, even if you're not on the call. All Zoom Q&A sessions will be recorded and uploaded to the course so you can watch them anytime later.
Does this course only focus on cone 6 glazes?
The concepts you'll learn in this class will be applicable to ALL glaze temperatures and you'll also learn how to raise or decrease the melting temperature of a glaze.
What if I live in another country and use different materials?
I'll be teaching you how to look at the underlying chemistry of glazes, which is applicable to all materials around the world. All you need is the chemical analyses of your materials, which should be available from your ceramic supplier.
Why are the prices in US Dollars?
Since my students are international, USD is the most “universal” currency option. CAD pricing is coming soon!
What's your refund policy?
I'm offer a 12-day money back guarantee from the release of Module 1. So you can complete the first 2 Modules and attend the first 2 Zoom Q&A sessions before deciding if you want to continue with the course. Refund requests must be received by 5pm on the Saturday of the Week 2 Zoom call. The exact date is listed in the Terms and Conditions.
Love From AGC Students
Love From My Community
Your Instructor - Sue McLeod
I’ve been mixing my own glazes from scratch since my 2nd year of art school in 2009. Learning to mix glazes solidified my love for ceramics. It added a whole other element to working with clay that I didn’t even know existed when I started.
Chemistry was my favourite subject back in high school and it was so fun to be reunited with this subject, both on an artistic level and in such a useful way.
For 6 years, I worked as a ceramics studio technician at a busy public studio in Victoria, BC, Canada, where it was my job to mix and maintain the glazes for the studio and fire the kilns. During my time in this position, I was able to really apply all the glaze chemistry I had learned in various courses in order to troubleshoot studio glaze issues, improve the chemistry of problematic glazes and study the thousands of fired pots coming out of the kilns over the years.
Learning about glaze chemistry is an endless, lifelong journey. There's so much to explore and I would love to help you get started on your own glaze chemistry journey.
Not ready to dive into glaze chemistry yet? Check out my blog and articles published in Ceramics Monthly magazine for lots of free information, or you may be interested in some of the other classes and workshops I have available online.
Questions?
All questions about the workshop can be sent through my website contact form. I'd love to hear from you!