Wheel guide · Intermediate
The trick to a closed pot is that the air does half the work.
Seal the top of a thrown form and you trap a pocket of air inside it. That pocket pushes back. It is the reason a closed pot can carry a belly that would fold an open one flat, and it is the reason people who have never tried this assume it is much harder than it is. Here is the whole technique in words you can hold in one hand, and videos you can watch with clean ones.
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A closed pot is thrown from the top down
Seal the top of a thrown form and you trap a pocket of air inside it. That pocket resists being squashed, so the wall you are not touching stays where it is while you press on the wall you are. It is why a closed pot carries a belly that would fold an open one flat. Getting there is one technique with one hard requirement, and the requirement is decided before you ever start closing.
The question that settles it before you collar anything
Is there more clay in the top third of your wall than in the bottom third? Collaring squeezes a wide circle into a narrow one, and the clay you close with is the clay you left in the rim. A thick top gathers and thickens as it comes in. A thin top folds, and a fold never throws back out. Nothing you do afterward rescues a wall that was tapered the wrong way.
So: two to three pounds, a clay body with some grog in it, walls around three eighths of an inch and heavier at the top, and a floor around three quarters. B-Mix with Grog, Speckled Buff and 52 Buff all behave. Save our #16 Porcelain for after you have done a few.
Once it is sealed, the air lets you do things an open pot would never survive: paddle flat sides into it, push the profile around with a rib, cut a neck into the crown, or cut the lid off at leather hard and keep a jar and a lid that fit each other perfectly.
01 · Why this page is built the way it is
Reading it and watching it are two different skills, and you need both
Watch somebody close a pot and it looks like nothing. Two hands close in, the hole gets smaller, the hole disappears. Eight seconds. You come away certain you could do that.
Then you try it and the wall folds over on itself like a wet paper bag and you have no idea which of the eight seconds you got wrong.
That gap is the whole problem. Video is unbeatable at showing you how fast something happens. How wet the clay looks. How much pressure a hand is actually putting on a rim, which is almost always less than you assumed. It is terrible at telling you why any of it is happening, because the reasons are invisible and the person doing it stopped noticing them a decade ago.
Words are the opposite. A sentence like “the clay you collar with is the clay you left in the rim, so a thin rim gives you nothing to close with” is not fun to read and it would be boring to watch. It is also most of the technique. Once you are carrying that sentence, the video stops being magic and starts being evidence.
There is a practical reason too. You cannot pause a video with clay on your hands. You can glance at a list.
So this page does both on purpose. Read the steps first. Watch the hands second. Then put the list on your phone, prop it against the splash pan, and go be wrong a few times, which is the only part of this nobody can do for you.
The order we would actually use
Read the checklist once, all the way through, before you watch anything. Then pick one video and watch it end to end without skipping. Then read the checklist again. The second read is where it lands, because now you have pictures to hang the sentences on.
02 · What you are actually making
A pot with no opening, and a pocket of air doing structural work
An enclosed form is a thrown pot whose wall closes over the top. No lip, no mouth, no way in. The moment it seals, the air inside stops being air in a room and starts being part of the pot.
- The closure. Where the wall met itself and shut. It is the thinnest, driest, most recently handled clay on the whole pot, which is why it is the first thing to crack if you do not compress it.
- An even wall. Every collaring pass thickens the wall as it narrows the circle. Even walls are what let you shape the pot afterward instead of finding the one thin patch with your thumb.
- The belly. The widest point, and the last place you can still reach with a hand. Push it out before the opening gets smaller than your fist, not after.
- Trapped air. Squeeze the pot anywhere and the pressure inside rises a little, and pushes back everywhere else. A little is enough. This is the whole reason closed forms hold shapes open ones cannot.
- A thick floor. Thicker than you would leave on a mug, because you will trim this pot upside down and you need something to trim into.
- A pinhole. Put in later, before the pot ever gets near a kiln. Section 07 is entirely about this and it is the one part of the page we would rather you did not skim.
It is not a balloon
The air is not holding the pot up like a beach ball. Clay is doing that. What the air does is resist a change in volume, so the wall you are not touching stays where it is while you press on the wall you are. Push a dent in one side of an open bowl and the other side follows it in. Push a dent in a closed form and the other side pushes back.
It feels firmer than it is
A sealed form under your hands feels like clay that has already firmed up. It has not. It is the same wet clay it was thirty seconds ago and it will still slump if you leave it on the wheel head with a fat belly and a thin base. Trust the feel for shaping, not for structure.
Water cannot get out
This is the one nobody mentions. Every drop of water inside that pot when you seal it is staying inside that pot. It pools in the floor, softens the base, and adds days to the drying. Sponge the inside dry before you start closing. It is the cheapest habit on this page.
03 · Pick a lane
Three ways to get to a sealed pot
They are not ranked. They fail differently and they suit different shapes. Most people learn the first one, use it for a year, and then find out about the other two.
Collar it shut
Throw a fat, short, thick-rimmed form. Then bring the wall in with both hands, wet, on a slow wheel, in several passes. The opening gets smaller each pass until it is a little cone, and you pinch that cone closed and smooth it into a dome.
This is the standard, the one nearly every demonstration shows, and the one the other two are variations of. Learn it first. It is also the one that punishes impatience most obviously, because collaring is a thing you do four times slowly rather than once quickly.
Dome it shut
Same start, different finish. Instead of pinching a cone closed at the top, you keep throwing the shrinking rim over toward the center like a very small, very steep bowl, and the last of it meets in the middle and welds under a rib or a fingertip.
It leaves a smoother crown with no pinched nub, which matters on bottles and on anything you plan to cut a neck into later. It wants less water and more control than method one, which is why it shows up mostly in porcelain videos.
Throw two halves and join
Throw two bowls the same width, let both firm up, score and slip the rims, and set one on the other upside down. Weld the seam, re-true the whole thing on a slow wheel, and you have a sphere much bigger than your hands could ever have closed.
This is how the genuinely large enclosed forms get made, and it is a different skill: it is a joining problem, not a collaring problem. We already have a whole page on joining thrown sections, so this one gets a pointer rather than a repeat.
If you only remember one thing about the difference
Methods one and two are decided at the rim. If you pull your walls thin and finish with a delicate rounded lip, you have already lost, whichever finish you were planning. A closing pot is thrown from the top down, and the top is where the clay has to be.
04 · Before you center anything
Six decisions that are much cheaper to make now
Every one of these is a decision people make halfway through instead, usually with wet hands and a pot that is already closing. Make them at the wedging table.
Start smaller than you want to
Two to three pounds for a first one. That gets you something between a grapefruit and a small melon, which is big enough to feel the air work and small enough that your hands can still meet around the top. Five pounds is a much harder pot, not a bigger version of the same pot.
Center it properly, because you get one chance
On an open pot you can true a wobble from the inside all day. On a closed one the inside is gone the moment you seal it. Whatever is off center when the hole shuts is off center forever, and it will show up again as a lean when it dries.
Pick a clay with some tooth
Grog is structure, and structure is what stops a fat wet belly sitting down. B-Mix with Grog is our usual answer, and Speckled Buff and 52 Buff both behave. Our #16 Porcelain will do it beautifully in experienced hands and will slump for everyone else, because a smooth body moves more and forgives less.
Throw thicker than feels right
Walls around three eighths of an inch, thicker still at the top, and a floor around three quarters. Collaring thickens the wall as it narrows, so anything you leave thin at the rim gets folded rather than gathered. You can trim weight off later. You cannot add it back.
Decide the widest point now
High belly, low belly, or straight up to a dome. It matters because the belly is the last thing you can reach, so it has to be right before the opening closes past your hand. Draw the profile on the back of a clay bag if that helps. Most people find it does.
Use less water than usual
Have a dry sponge on the wheel, not just a wet one. Everything you spill inside the pot lives there until the pot dries, and a soft wet floor under a heavy closed belly is the single most common way one of these collapses in the last thirty seconds.
05 · The list for your phone
Fifteen steps, in the order they happen
Nine steps, in the order they happen
This is the collaring method, because the other two are variations on it. Tap a step to cross it off. Nothing is saved when you leave the page, so it resets clean for the next pot.
This is the collaring method, which is the one to learn first. Tap a step to cross it off. Nothing is saved when you leave the page, so it resets clean for the next pot.
The step that is not on the list yet
The hole. It does not belong here because it does not happen at the wheel, and putting it in the middle of a throwing list is how it gets forgotten. It has its own section two scrolls down, and it is the only thing on this page that is not optional.
06 · The payoff
Now do the things you could never do to an open pot
Closing a pot is not the end of the job, it is the start of a different one. A sealed form will take pressure from the outside that would flatten anything with a mouth on it. This is why people bother.
Paddle flat sides into it
Let it go soft leather hard, hold it in one hand or rest it on foam, and smack it with a flat wooden paddle. Move the paddle around the pot rather than hitting the same spot, and stop before the clay sticks. Four facets makes a squared bottle. Six makes something that looks deliberate. This is the single most satisfying thing you can do with a closed form and it takes about ninety seconds.
Push the shape around with a rib
While it is still on the wheel and still wet, a rib on the outside will move the wall out or in and the air holds the rest of the pot steady. Small moves. The wall has no support from the inside anymore, so a rib that presses hard just makes a thin patch you will find later.
Cut a neck into the top
At leather hard, cut a small circle out of the crown and you have a bottle with a shoulder no open-throwing method would have given you. Add a coil around the opening and throw a neck up from it if you want more height. This is the classic route to a narrow-necked bottle, and it starts with a pot that had no opening at all.
Cut the lid off and keep both halves
Score a level line around the pot at leather hard, cut through with a needle tool on a slow wheel, and lift the top off. You now have a jar and a lid that fit each other perfectly, because they used to be the same pot. Clean up both edges, add a gallery if you want it to sit down rather than on, and stop dreading throwing lids.
Carve, stamp and roll texture on it
Anything you press into a closed form pushes against air rather than against nothing. Roulettes, stamps, chattering, carving through slip. All of it is easier on a sealed wall than on an open one, which is why so many heavily decorated bottles started life closed.
Leave it shut and make a rattle
Drop a couple of small bone dry clay pellets in before you close it. They shrink at the same rate as the pot, they never stick, and the finished piece rattles for the rest of its life. Children lose their minds over these. So do adults, quietly.
One thing the air will not survive
Do not squeeze a sealed form hard with both hands to feel the pressure. It is a great party trick right up to the moment the wall splits at the closure, and it splits at the closure because that is the thinnest clay on the pot. If you want to know how much give it has, press with one finger.
07 · Read this one twice
A sealed pot needs a hole before it is fired. Every time. No exceptions.
Air expands when you heat it. Trapped air in a kiln has nowhere to go, so it pushes on the inside of your pot with more force the hotter it gets, while the clay around it is getting weaker. Add the steam coming off any moisture still in a thick floor and you have a small pressure vessel in a room with other people’s work in it.
It does not crack politely. It bursts, and it takes the shelf and its neighbors with it.
When, and where
The moment you have finished shaping it, before it goes on a shelf. Under the foot is the usual spot, since nobody turns a pot over. It does not have to be hidden, it only has to exist. Then dry it slowly, because moisture can only leave through the wall and that one hole.
How big, and how to know it went through
A needle tool is enough. Push it in until the resistance disappears, which is how you know you reached the air. A hole that stops in the middle of a three quarter inch floor is a decoration and it will not save the piece. If you are not sure, ask an instructor.
When
After you have finished altering it and before it goes on a shelf to dry. Keep it sealed while the clay still moves, because that is when the air is useful. Once you are done shaping, put the hole in. If you know you are the kind of person who will forget, put it in immediately and accept a slightly softer pot.
Where
Somewhere you can live with. Under the foot is the usual answer, because nobody turns a pot over. Inside a recessed base, under a rim, or in the spot where a neck is going to be cut are all fine. It does not have to be hidden, it just has to exist.
How big
A needle tool is enough. This is not a vent that needs to move volume, it is a path that stops pressure building. One clean hole all the way through the wall beats three half-hearted dimples that never made it into the cavity.
Check it is actually through
Push the needle in until you feel it give. A hole that stops in the middle of a three quarter inch floor is not a hole, it is a decoration, and it will not save the piece. If you are not sure, ask an instructor before you set it on your shelf. That is a ten second conversation and everybody in a pink tee has had it before.
This is not a Clay Hole rule, it is physics, and it is the same in every studio on earth. Bisque runs to cone 05 here and glaze to cone 5½, and neither of them cares how nice your pot was.
08 · Now watch the hands
Five videos, five potters, none of them us
Two videos, two potters, neither of them us
Two, and they teach the same move differently. The first is four minutes with no talking, which is the fastest way to see how slowly this actually happens. The second is the same technique explained while it is done. Neither is ours, both are free, and nothing loads until you press play, so no player and no YouTube cookies arrive on this page unless you ask for them.
Five is all this needs. We looked at a lot more and most of them were the same eight seconds filmed from a different angle, so what is here is one video per job: the fastest way to see the whole move, two full teaching versions that disagree with each other in useful ways, and two that answer the question you will have the moment your first one works. Every title, channel and length was checked against YouTube itself rather than copied off a search page. Nothing loads until you press play, so no player and no YouTube cookies arrive on this page unless you ask for them.
Watch these two
The whole move with nobody talking over it, then the same thing with somebody explaining why as he goes.
Pottery Throwing Techniques 3: Throwing a closed in / enclosed form pot on the wheel
Four minutes, one take, a working production potter who is not performing for a camera. You can see exactly how slowly he collars and how many passes it takes, which are the two things every beginner gets wrong. If you watch one thing before you sit down, make it this one.
How to throw an Enclosed form on the wheel (intermediate)
Aimed squarely at somebody who can already throw a cylinder and has never closed one. He explains why he is doing things while he does them, which is exactly the gap a silent demonstration leaves. This is the closest thing here to a lesson.
Start here if you have four minutes
The entire move, no talking, no edit. Watch this before you read anything else on the page again.
Pottery Throwing Techniques 3: Throwing a closed in / enclosed form pot on the wheel
Four minutes, one take, a working production potter who is not performing for a camera. You can see exactly how slowly he collars and how many passes it takes, which are the two things every beginner gets wrong. If you watch one thing on this page, make it this one.
The full version, twice, by people who disagree
One collars and pinches. One domes it over with barely any water. Watching both is how you find out which parts are the technique and which parts are just how that person happens to do it.
How to throw an Enclosed form on the wheel (intermediate)
The talked-through version of the video above, aimed squarely at somebody who can already throw a cylinder and has never closed one. He explains why he is doing things while he does them, which is exactly the gap silent demonstrations leave. This is the closest thing here to a lesson.
93. Throwing a Closed Porcelain Vase / Bottle with Hsin-Chuen Lin
Method two, in porcelain, by somebody who has posted hundreds of throwing demonstrations and throws with almost no water at all. Watch what his hands do at the very top: he does not pinch it shut, he keeps throwing the rim over until it meets itself. That is a genuinely different move and it is worth stealing.
Then what do I do with it
The question everybody asks about forty seconds after their first one works.
10 Tips on How to Throw Closed Form Pottery, With 3 Projects
Tips first, then three actual things to make with what you just learned. The most watched video on this page by a distance, and the one to send somebody who has closed a pot, felt very pleased with themselves, and then stood there holding a clay ball with no idea what it is for.
How To Make A Lidded Jar In One Piece, cut off lid
Closed form in, lidded jar out. He throws it shut, lets it firm up, cuts the lid off and cleans up both edges, and the fit is perfect because the two halves used to be one pot. If throwing lids has been quietly ruining your month, this is the video that fixes it.
Neither video is ours and neither potter is affiliated with The Clay Hole. Both cards link straight to the original. If one of them helps you, go and say so on their video rather than here.
None of these videos are ours and none of these potters are affiliated with The Clay Hole. Every channel is credited above and every card links straight to the original. If one of them helps you, go and say so on their video rather than here. We keep a longer list of videos from potters we admire if you want to keep going.
09 · The unglamorous half
Trimming something with no opening, and drying something with no way out
Nobody films this part because it takes a week and nothing happens. It is also where most closed forms are actually lost.
It will not sit on the wheel head
A domed top has nothing flat to rest on, so you cannot just flip it over and trim. You need something to hold it: a bisque chuck, a foam bat, or a fat coil of clay pressed into a ring on the wheel head, which costs nothing and works fine. Nest the dome in the ring, tap it true with the wheel turning, and trim the foot as normal.
Trim before you pierce it, if you can
The trapped air is holding the wall steady against your trimming tool, and you will feel the difference the moment it is gone. Trim first, then put the hole in. If there is any chance you will walk away and forget, reverse that order. A slightly harder trim is better than a piece that never gets fired.
Trim more than you think
You threw a thick floor on purpose and now it is a heavy pot that will dry unevenly. A closed form should feel surprisingly light for its size when it is finished. If it feels like a rock, the floor is still in there.
The inside air stays humid
Moisture can only leave through the wall, or through the hole you put in. That is why a closed form takes noticeably longer to dry than an open pot of the same size, and why an unpierced one can sit for a fortnight feeling bone dry on the outside while the floor is still damp.
Dry it slower than it looks like it needs
Loose plastic for the first couple of days, then off. Rotate it a quarter turn every day or so, because the side facing the room dries first and the pot shrinks unevenly. Thick floor, thin closure and a sealed middle is a recipe for uneven shrinkage, and uneven shrinkage is what makes cracks.
Bone dry means bone dry
Hold it against your cheek. Cold means damp. On a piece with a thick base and a sealed cavity, give it a few more days than you would give a mug, then a few more after that. Bisque is free here, so the only thing waiting costs you is patience.
10 · Diagnosis
Something went wrong. Tell us which thing
Eight failures we see most often, what actually caused each one, and what to change next time. None of them mean you should not be attempting this.
The four we see most often, what actually caused each one, and what to change next time. None of them mean you should not be attempting this.
Usually
Not enough clay in the top of the wall.
This piece
Reclaim it.
Next time
Leave the top third heavy and collar in four passes.
A fold is almost always a thickness problem wearing a technique problem’s clothes. Collaring squeezes a big circle into a smaller one, and that clay has to go somewhere. If the wall is thick it thickens further and holds. If it is thin it buckles, and once a fold starts it will not throw back out.
11 · Questions we get at the wheels
Nine straight answers
Is this actually an advanced technique? Should I wait?
If you can pull a clean cylinder, you can close one. The skills are not exotic, they are unfamiliar, and the first three attempts are the whole curriculum. Nothing about it is gated by Level, nothing needs special equipment, and the worst realistic outcome is that you learn a lot and reclaim two pounds of clay. Plenty of members close their first pot inside their first couple of months.
Do I really have to put a hole in it?
Yes, and it is the only thing on this page we would call non negotiable. Heated air expands, trapped heated air has nowhere to go, and a sealed piece in a kiln is a pressure vessel surrounded by other people’s work. One needle hole all the way through the wall solves it completely and permanently. Put it under the foot and nobody will ever see it.
With a hole in it, is it safe? Will it still blow up?
With a real hole it is no more risky than any other pot, and it goes in a kiln alongside everything else. The remaining risk is the same one every thick piece has, which is moisture. A closed form holds water in its floor longer than an open one, so give it extra drying time and check that it is properly bone dry rather than just dry to the touch.
How much clay should I start with?
Two to three pounds. That is a pot you can still get a hand inside while you shape the belly, and one your hands can comfortably meet around while you collar. Five pounds is not the same pot scaled up, it is a harder pot, because the circle you have to close is wider than your two hands want to travel in one pass. Get three small ones right before you go up.
Which of our clay bodies is best for this?
Anything with grog in it. B-Mix with Grog is the easy answer, and Speckled Buff and 52 Buff both hold a fat wet belly without complaint. Half & Half and plain B-Mix are perfectly doable. Our #16 Porcelain is the one to save for later: it is smooth, it moves more, and it slumps sooner, which is a lot to manage at the same time as learning to collar. Clay starts at $28 for a 25 lb bag before your Level discount.
How do I trim something with no opening?
You hold it in something rather than on something. A bisque chuck if you have one, a foam bat, or a thick coil of clay pressed into a ring on the wheel head, which is free and works. Set the dome down into it, tap it true with the wheel turning, and trim the foot the way you normally would. Trim before you pierce it if you can, because the trapped air braces the wall against your tool.
Does a closed form cost more to fire?
Bisque is free at any size. Glaze firings are five cents per cubic inch with a $4.80 minimum, measured on the box your piece fits inside rather than on the piece itself. So a six inch sphere is measured as a six inch cube: 216 cubic inches, which is $10.80. A round pot always pays for the corners it does not use, which is worth knowing before you make a very big one. Glaze fires to cone 5½.
Can I make a really big one?
Not by collaring, past a point. Your hands have to be able to surround the opening, and that puts a ceiling on the diameter you can close in one piece. Past that ceiling everybody switches to method three and throws two halves and joins them, which is a different skill with its own page. If you have ever wondered how somebody made a sphere the size of a beach ball, that is how.
Can I glaze it like a normal pot?
Yes, with one thing to think about: your pinhole. Glaze will happily fill and seal a needle hole, and a glaze-plugged hole is the same as no hole. Keep glaze off it, or clear it with the needle before the piece goes on the cart. Otherwise it is an ordinary outside-only glazing job, and a fully rounded form is one of the nicest things to dip you will ever hold.
Go seal something
Your first one will fold. Make it anyway.
Nobody closes a clean pot on the first attempt. The clay teaches you how slow slow actually is, and there is no way to be told it. What we can give you is 29 wheels, an instructor in every single class, free bisque firings while you get it wrong, and somewhere to leave a very round pot alone for a week while it does what it needs to do.
That was the short version. There is a much longer one behind the Comprehensive toggle at the top of this page: three ways to seal a pot, the anatomy of a closed form, six things to do with one afterwards, trimming and drying it, five videos, eight ways it goes wrong and nine questions we get at the wheels.
12896 S Pony Express Rd, Suite 100, Draper, Utah 84020. Stuck partway through a closed form and not sure whether it is worth saving? Text the studio on 385-241-5528 and describe it. We have all reclaimed one of these.