You can move this picture: drag it, press and hold then drag on a touch screen, or use the arrow keys.Printable guide 06.13

The Clay Hole University · Advanced Throwing

Throwing Moon JarsPrintable pottery guide

Two bowls thrown to the same number, joined at the equator inside a window a few hours wide, and re-thrown until the seam is gone.

$10.005 guides, 1 free
  • Skill level: Advanced
  • 32 printable pages
  • 9 video picks
  • 8-question quiz + answer key

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

What is the Throwing Moon Jars printable guide?

It is a printable workbook edition of The Clay Hole University’s free “Throwing Moon Jars” lesson. It covers the five stages: throwing two bowls to the same number, waiting for the stiffness window that is the whole ball game, joining them at the equator, re-throwing the joined form until the seam is gone, and then the hole, the neck and the foot. On paper it adds a jar log for the weights, the diameters and the clock, a diagnosis section for the nine ways it goes wrong, a one page card for beside the wheel, a quiz with a full answer key, and a glossary.

Prefer to read it online first? The “Throwing Moon Jars” lesson is free, and always will be.

  • 32printable pages, US Letter
  • 8quiz questions, with a full answer key
  • 9hand-picked videos, each with a QR code
  • 16glossary terms in plain language
  • 2workbook pages you fill in yourself
Why a printable, for this one

The whole thing turns on a window a few hours wide

A moon jar is two bowls and a clock. Throw them too far apart in stiffness and the join will not weld. Wait too long and neither half will move when you re-throw it. The window where both are true is a few hours wide, and you cannot see it, you can only feel it and time it.

Everything that decides one is a number or a clock. Two weights, two rim diameters, and when you covered each half. Those are exactly the things nobody remembers by the time the seam opens up in the kiln.

So this guide is built to be open with a pencil next to it from the first bowl onwards. Write the two weights, write the two diameters, write the time you covered them. The jar you lose this way still teaches you the next one.

Look inside

Real pages, for a pot made across two days

These are actual pages from the guide, shown here with the sample watermark. The full guide has none.

  • Page 5 of the “Throwing Moon Jars” printable guide: what a moon jar is, shown with the sample watermark
    What a moon jar isTwo bowls joined at the equator, and why the form is defined by a seam you are going to spend an hour making disappear.
  • Page 12 of the “Throwing Moon Jars” printable guide: joining the halves, shown with the sample watermark
    Joining the halvesStage three, step by step: scoring, slipping and welding a join that has to survive being thrown again.
  • Page 17 of the “Throwing Moon Jars” printable guide: the jar log, shown with the sample watermark
    The jar logEverything that decides a moon jar is a number or a clock. The two weights, the two rim diameters, and when you covered them.
  • Page 21 of the “Throwing Moon Jars” printable guide: nine ways it goes wrong, shown with the sample watermark
    Nine ways it goes wrongEach one with what really caused it, and a box to tick for the ones that keep happening to you.
Flip through the free sampleTen pages, free, no email required.
Paper beats the screen here

Why a moon jar, of all things, belongs on paper

This pot is made in stages across more than one day, and the things that decide it are numbers taken hours apart. Nothing on a screen holds that together.

  • It carries across two days

    You will not finish a moon jar in one sitting. The page keeps stage one’s numbers where stage three can still read them.

  • It makes the stiffness window a written thing

    Write down when you covered each half, and the window stops being a guess and becomes a time you can repeat or correct.

  • It matches the two halves honestly

    Two rim diameters written down beat two rims you think looked about the same. That is the difference between a join that welds and one that opens in the kiln.

  • One card lives by the wheel for good

    The five stages with the explanations taken out, on a single page you can pull out of the binder.

How the guide is built

Built for a pot made in five stages, not one sitting

Every guide in the series is designed as a workbook first and a document second. For this one, that means:

  • A learning dashboard before page one

    What you will learn, what you need on the tray, the mistakes that get made first, and what a good join actually feels like under the rib.

  • The complete lesson, redesigned for paper

    All five stages in order: the two bowls, the stiffness window, joining, re-throwing, and the hole, neck and foot.

  • The stiffness window, with a section of its own

    It is the whole ball game, and it is the part every video skips because it is hours of nothing happening.

  • Steam, slow drying, and where moon jars crack

    A big hollow form with a join in the middle of it has specific places it fails, and they are named rather than left to luck.

  • Videos you can reach from a printed page

    Nine videos chosen for what they show rather than who made them, each with a note on why it is worth your time and a code that goes straight to it.

  • Plain words for the jargon

    A sixteen term glossary, from the equator and the weld to soft leather hard and the chuck, written the way we would explain it at the wheel.

Why the University is free

The lesson is free. It always will be.

All of the teaching in this guide comes from the free “Throwing Moon Jars” lesson at The Clay Hole University. No paywall, no sign-up, no catch.

A moon jar looks like something you would need a master to teach you, and really it is two bowls, a clock and a lot of patience. That is worth knowing, so the lesson stays free, for anybody, anywhere.

The University is free and stays free. The guides are the version rebuilt for paper with an unreasonable amount of care, and buying one keeps the free side going.

Thank you. Genuinely.

Dan Pearce, founder of The Clay Hole
Collect them

Build a little pottery library

Every guide carries a permanent number. This one is 06.13, the thirteenth guide in Advanced Throwing. The series is designed to live together in a binder, section by section, so the craft ends up on your shelf in the order you learn it.

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
Where this leads

What to learn once the seam disappears

These lessons pick up where this one leaves off. Each one is free to read now.

Good questions

Before you buy

Is this different from the free lesson?
The teaching is the same, and the free lesson is complete. The printable adds a jar log for the weights, diameters and times, a diagnosis section with boxes to tick, a one page card for beside the wheel, a printed quiz with an answer key, and a glossary.
How do I know when the stiffness window is open?
It has its own section, because it is the whole thing. The short answer is soft leather hard on both halves at once, and the useful answer is writing down when you covered them so the window becomes repeatable.
My seam opened up in the kiln. Why?
Usually the two halves were at different stiffnesses when they were joined, so the weld was never a real weld. It is the first thing the diagnosis section separates out.
Do the two bowls have to be identical?
The rims do. The guide has you throw to a measured diameter with calipers rather than by eye, because two rims that look the same are usually not.
Can I make one in a single session?
No, and anything that tells you otherwise is skipping the wait. The stiffness window is hours wide and it is not something you can rush with a heat gun without paying for it later.
Is this too advanced for me?
It assumes you can throw a bowl to a number and collar a rim. If you can do that, the moon jar is mostly patience and bookkeeping, which is why the log is in here.
I am not at The Clay Hole. Is it still useful?
Yes. The stages, the window and the numbers are the same wherever you throw. Anything specific to our studio is marked as ours, and the studio numbers carry the date they were true.
Do I need a fancy printer?
No. It is designed 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.
Can I print it in black and white?
Yes. Nothing depends on color, and we looked at the workbook pages in grayscale to be sure.
Can I use it on an iPad or laptop instead?
Yes. Every QR code in the guide is also a tappable link, so on a screen you just tap instead of scanning.
How do I get it after I buy?
Right after checkout you get a download link by email and on your order confirmation page. Each link works up to seven times.
What if the guide gets updated?
Every edition carries a version number. When we correct or improve a guide, everyone who bought it gets an email with the new edition at no charge.
Can I share it with my class or studio?
Please don’t. It is licensed for your own personal use. Anyone can read the full lesson free online, and the printable is here if they want their own copy.

Go and lose the first one

Print it tonight. Throw two bowls to the same number, write down when you covered them, and treat the first jar as the one that teaches you the second.

Get the printable · $10.00

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.

You may not remove or obscure copyright notices, watermarks, attribution, or other ownership information, or sell, republish, or commercially exploit modified or derivative versions of the guide.

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.

Digital guides, immediate delivery, and refunds

These are digital products delivered electronically and made available for use immediately after purchase. Unlike a physical book, a downloaded digital file cannot meaningfully be returned to us once it has been delivered.

By completing your purchase and requesting immediate access to the guide, you consent to digital delivery beginning immediately. Where applicable law provides a cancellation or withdrawal period for digital content, you acknowledge that beginning the download, access, or delivery of the digital content may cause that cancellation or withdrawal right to end.

Once access to or delivery of the purchased digital guide has begun, the purchase is final and non-refundable except where a refund, replacement, cancellation, or other remedy is required by applicable law.

If the file you receive is corrupted, inaccessible, materially different from what was described, or there is a genuine technical problem with delivery, please contact us. We would much rather fix the problem than leave you staring angrily at a PDF that refuses to PDF.

Terms version 2026-09-19b