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The Clay Hole University · Glazing

What Pottery Glaze Actually IsPrintable pottery guide

What glaze really is, on paper: why it is glass, what melts it and what holds it on, why some pots craze, why a surface is gloss or matte, what food safe rests on, and a log for every glaze you use.

$5.005 guides, 1 free
  • Skill level: Beginner
  • 20 printable pages
  • 5 video picks
  • 8-question quiz + answer key

Flip through the free sample
  • Instant download
  • Prints on any printer
  • The lesson stays free
The printable, at a glance

What is the What Pottery Glaze Actually Is printable guide?

It is the free “What Pottery Glaze Actually Is” lesson rebuilt for paper: six facts about glass on clay, the three jobs in every glaze and three helpers, why a glaze crazes, what makes gloss, satin and matte, what a food safe claim rests on, what goes wrong and what it means, and five videos worth your time. Built to be printed, kept beside you and written in.

Prefer to read it online first? The “What Pottery Glaze Actually Is” lesson is free, and always will be.

  • 20printable pages, US Letter
  • 8quiz questions, with a full answer key
  • 5hand-picked videos, each with a QR code
  • 17glossary terms in plain language
  • 2workbook pages you fill in yourself
For anyone who has ever wondered what is in the bucket

Know what you are looking at.

Glaze looks like magic until somebody tells you it is glass. Once you know that, a lot of the confusing parts stop being confusing: why the bucket looks nothing like the fired pot, why some pots craze, why the same glaze never looks the same twice.

The guide is the short version of what is really going on. What becomes the glass, what makes it melt, what stops it running off the pot, how surfaces differ and what a finished pot has to be before anyone calls it food safe.

It also gives you something a web page cannot: a log to write in. The glaze and the clay, the coats, the surface, whether it fit, and the one change you would make. After a few pots you can see which pairings work and which surprise you.

Look inside

Real pages, for beside you when a pot comes out strange

These are actual pages from the guide, shown here with the sample watermark.

  • Page 3 of the “What Pottery Glaze Actually Is” printable guide: before you begin, shown with the sample watermark
    Before you beginOne page before anything else: what you will learn, what you need, what is worth knowing, the common pitfalls, and what a good result looks like.
  • Page 5 of the “What Pottery Glaze Actually Is” printable guide: the three jobs, shown with the sample watermark
    The three jobsSilica, flux and alumina, and the three helpers: boron, colorants and opacifiers.
  • Page 10 of the “What Pottery Glaze Actually Is” printable guide: when it goes wrong, shown with the sample watermark
    When it goes wrongRunning, dry and rough, crazing, shivering, crawling and pinholes: what each one looks like and what it means.
  • Page 13 of the “What Pottery Glaze Actually Is” printable guide: every glaze, and what it did, shown with the sample watermark
    Every glaze, and what it didA log to write in: the glaze and clay, the coats, the surface, whether it fit and the one change.
Flip through the free sampleTen pages, free, no email required.
Why this one belongs on paper

A reference you read a pot against

You look at the pot, then at the page. Paper suits that.

  • The idea on one page

    The three jobs, how to read a surface and what to do about crazing sit on a single page you can pin up beside the glazes.

  • A reason for every rule

    Each claim comes with its reason: why silica needs a flux, why crazing is a fit problem and why a dry, rough surface is not matte.

  • A log for your own pots

    Columns for the glaze and clay, the coats, the surface and whether it fit. A few pots of notes beat a memory of what you did.

  • It does not mind a dusty bench

    A page stays where you put it. It does not lock its screen, and you can wipe it down with the rest of the bench.

How this one is built

Rebuilt for paper, not printed from a web page

Every guide in the series is set from scratch for print. Here is what that meant for this one.

  • Read against our other lessons

    We checked the lesson against the studio’s own rules and our lessons on dipping, brushing, test tiles and glaze problems. Where they differed, the guide now says what those pages say.

  • Plainer promises about food

    A food safe claim rests on a fully melted, well fitted glaze on a vitrified pot, and it belongs to the glaze maker. The guide says so and points to our Food Safe Lookup.

  • Crazing put where it belongs

    Crazing is a fit between glaze and clay, not something you did with the dip. The guide says so everywhere it comes up.

  • Video notes that say what the video shows

    Each of the five videos has a note checked against its description and chapter list, so the guide promises only what a video covers.

  • A quiz that explains itself

    A short quiz, and an answer key that gives the reason behind every answer rather than only the letter.

  • Codes that keep working

    Every link is a short Clay Hole address. If a page moves, we repoint the address and your printed copy still goes to the right place.

Why the University is free

The lesson is free. It always will be.

All of the teaching in this guide comes from the free “What Pottery Glaze Actually Is” lesson, and that lesson is not going anywhere.

Glaze looks like magic until somebody tells you it is glass.

A crazed surface is not a personal failure. It is a fact about two materials.

Dan Pearce, founder of The Clay Hole
The series

Build a little pottery library

Every printable guide in The Clay Hole University series takes one free lesson and rebuilds it for paper, with workbook pages, a glossary and a quiz with a worked answer key. Each one keeps its number for good, so a guide you buy today is the same guide in the same place next year.

Put any five printable guides in your cart and the cheapest one is on us. Put in nine and the two cheapest are on us. It happens automatically at checkout, no code to remember.

See every printable guide

  • 5guides in your cart1 on us
  • 9guides in your cart2 on us
Sits next to

Three lessons that pick up where this one leaves off

Each one is free to read online, and the codes in the guide take you straight there.

Questions

Good to know

How is this different from the free lesson?
The teaching is the same, and the free lesson is not going anywhere. The guide is that teaching rebuilt for paper: a learning dashboard at the front, a log to write in, a one page summary, a glossary and a quiz with an answer key that explains every answer.
Do I need any chemistry?
No. The guide uses three plain ideas: something becomes glass, something makes it melt, and something stops it running off. The glossary covers every word you might trip on.
Will it tell me whether my mug is food safe?
It tells you what a food safe claim rests on: a fully melted, well fitted glaze on a vitrified pot, and a claim that belongs to the glaze maker. For the jars on our wall, it points you to our Food Safe Lookup.
Does it cover mixing my own glaze?
Only as far as explaining what is in one. It is about understanding glaze, not a recipe book, and mixing is a separate lesson with its own guide.
Do I need to be a member to use it?
You do not need to be a member to read it. Where a rule is only ours, such as how we fire or what we ask before a glaze you bring in goes near a kiln, the guide says so, so you can tell a Clay Hole rule from a fact of the craft.
Is this too early for me?
It is marked Beginner. You do not need to have glazed anything yet, although it helps to have a glazed pot near you to look at.
Do I need a fancy printer?
No. It is set for an ordinary home or office printer on regular US Letter paper, with nothing important near the edges, so normal printer margins cut nothing off.
Does it print in black and white?
Yes. The text, the tick boxes and the tables are black on white, and color is used for headings and small labels.
Can I print just part of it?
Yes, and most people do. The one page summary and the log are the two worth having beside you. They are numbered pages like any other, so you can print those and leave the rest on a screen.
Do the videos work on paper?
Each video has a short note and a code that takes you straight to it, so you can scan it from the page.
How does delivery work?
It is a digital download. The link arrives by email and on the order confirmation page right after checkout, so you can have it printed the same evening.
What happens if the guide is updated?
Every edition carries its version number on the last page. When we correct or improve one, the new edition replaces the old one in the shop, and we can send the updated link to anybody who already bought it.
Can I share it?
It is licensed for your own use. Print as many copies for yourself as you like, on as many of your own devices as you like. Please do not pass the file on, upload it or use it with a class or a group without asking us first.

Read the pot, not just the bucket

Know the three jobs, tell crazing from shivering, and tell matte from unfinished. The guide keeps all of it in front of you when a pot comes out strange.

Get the guide · $5.00

The Clay Hole University Printable Guide Terms

Licensing, safety, digital delivery, and refund terms

Your copy is yours. The guide is not.

Your purchase gives one individual purchaser a limited, non-exclusive, non-transferable license for personal use only. You may download the guide to your own devices, print copies for your own use, write all over them, spill clay water on them, replace a coffee-damaged copy, and generally use the heck out of what you bought.

What you may not do is distribute the guide to anyone else, whether you charge for it or not.

That means you may not share, forward, email, upload, post, publish, copy, reproduce, resell, sublicense, redistribute, or otherwise provide the guide, or any substantial portion of it, to another person. You may not place it in a shared drive, group chat, membership library, online community, file-sharing service, studio resource folder, classroom packet, employee handbook, course, workshop, or other shared collection. You may not make copies for students, members, employees, friends, classes, studios, schools, groups, or organizations.

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Purchasing the guide does not transfer ownership of its copyrighted text, photographs, illustrations, graphics, layouts, worksheets, or other original content. Those rights remain with The Clay Hole and their respective rights holders. Copyright law protects the expression contained in these guides, while ideas, methods, techniques, and processes may have different legal treatment.

If you would like to use one of our guides with a class, studio, school, team, or other group, contact The Clay Hole about permission or group licensing. Please do not make twenty copies and call it manifesting.

Pottery is wonderfully unpredictable. It also carries real risk.

We work hard to make The Clay Hole University accurate, useful, practical, and ridiculously thorough. But pottery is a hands-on craft involving countless variables that no written guide can completely control or anticipate.

Depending on what you are doing, ceramics may involve extreme heat, kilns, electricity, gas, flame, sharp tools, spinning machinery, heavy equipment, pressurized equipment, silica-containing dust, fumes, chemicals, raw materials, stains, oxides, glazes, combustible materials, hot surfaces, breakable objects, and other hazards capable of causing serious injury, illness, property damage, fire, or worse.

These guides are provided for general educational and informational purposes. They are not a substitute for hands-on training, competent supervision, your studio’s safety procedures, applicable laws or codes, Safety Data Sheets, or the instructions and warnings supplied by the manufacturers of your clay, glaze, chemicals, tools, kilns, equipment, protective gear, or other materials.

Studios, kilns, clay bodies, glazes, firing schedules, electrical systems, ventilation systems, equipment, environmental conditions, application thicknesses, material formulations, and individual techniques vary enormously. Something that works beautifully in one situation may fail spectacularly in another. That is part of pottery. Occasionally, it is a very expensive part of pottery.

You are responsible for determining whether any technique, material, combination, firing schedule, tool, or process described in a guide is appropriate and safe for your specific circumstances before using it.

Use appropriate protective equipment. Use adequate ventilation and dust control. Read manufacturer instructions and Safety Data Sheets. Follow your studio’s rules. Obtain qualified instruction when a process or piece of equipment requires it. Test materials and techniques before committing important work to them. If you do not understand how to perform something safely, do not proceed until you do.

Never assume that a ceramic surface, glaze, clay body, firing method, finished vessel, repair, decoration, or other result is food-safe, microwave-safe, dishwasher-safe, oven-safe, structurally sound, chemically stable, or suitable for any particular purpose solely because it appears in or is discussed in one of our guides. Verify suitability independently when it matters.

Ceramics also refuses to sign contracts promising beautiful results. Colors change. Glazes move. Kilns have opinions. Pots crack. Materials interact unexpectedly. Manufacturers reformulate products. Equipment behaves differently. The Clay Hole does not guarantee any particular aesthetic, functional, firing, glazing, structural, or other result.

By choosing to use the information in a guide, you accept responsibility for your own materials, equipment, workspace, safety decisions, testing, methods, and results. To the fullest extent permitted by applicable law, The Clay Hole and its owners, employees, contributors, and affiliates are not responsible for injury, illness, property damage, lost work, failed projects, kiln or equipment damage, financial loss, or other loss arising from or related to your use of, or reliance upon, the guide.

Nothing in these terms excludes or limits any right or liability that applicable law does not allow us to exclude or limit.

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Terms version 2026-09-19b