How is a cricket ball made? Cork, leather and six rows

A cricket ball is four pieces of leather stitched around a lump of wound cork, and almost every argument in the game about swing, seam, softness and the state of the ball at tea is really an argument about how that object was assembled. How is a cricket ball made is not an equipment question. It is a question about why the same bowler with the same action gets a completely different game in Leeds and in Nagpur.

The finished thing is deceptively simple. Take a ball apart, which is easier than it sounds once the stitching is cut, and you find perhaps five materials and no moving parts. What you cannot see from the outside is that every one of the properties a bowler cares about was decided by somebody at a bench: how proud the seam stands, how long the shine lasts, how quickly the leather softens, whether the thing holds its shape for eighty overs or goes out of round in thirty.

This is what happens at that bench, and what each decision costs.

What is actually inside a cricket ball

Start in the middle, because the middle is where the weight is.

The core is cork. Not a single cut plug like a wine stopper, but cork granules ground down and compressed under pressure into a small dense sphere, which is then built up in layers: a centre, further slices pressed and bonded around it, sometimes with rubber blended in to control the rebound. What the maker is aiming at is a small heavy ball that is uniformly dense in every direction, because any lump or void in the core will show up later as a ball that does not behave the same way on every face.

Cork is the traditional answer for a reason worth stating plainly. It is light for its stiffness, it recovers its shape after being hit, and it does not shatter. A solid rubber core would be too lively and a wooden one would split. Cork sits in the narrow band where a ball can be struck at speed by a bat, thousands of times across an innings, and still come back roughly the same shape.

Around the core goes the quilt: layer after layer of worsted wool yarn, wound under high tension by machine, crossing over itself so that no single direction is stronger than another. Several layers at minimum, more in a better ball. This is the part almost every explanation skips, and it is the part that decides most of what the ball does.

The winding is where the bounce comes from

Tension in the winding is the maker's main control over hardness. Wind tighter and the finished ball is harder, comes off the bat faster, carries to the keeper better and stays hard for longer. Wind looser and it is softer from the first over and goes dead quickly.

That hardness is also what keeps the ball round. A cricket ball goes out of shape from the inside, not the outside. Repeated impact compresses the wound layers unevenly, and once the package underneath the leather is no longer a sphere the leather cannot make it one. A ball that has "gone out of shape" has usually not had its cover damaged at all. Its quilt has been beaten flat on one side.

The winding is also the reason weight is a design output rather than an input. The maker cannot simply add a gram at the end. Weight comes from how much yarn goes on and how tightly it is pulled, so the tension has to be right during winding, and the ball is weighed afterwards to see whether it landed inside the legal band. Balls that fall outside it are downgraded or scrapped.

There is a second thing the quilt does. It couples the leather to the core. When a bat hits the ball, the energy has to pass through the cover, through the wound layers and into the core and back out again. A well-wound ball returns that energy quickly and consistently. A badly wound one absorbs it, which is what people are describing when they say a ball has "died" long before it looks worn.

• 4Quarters of leather in a first-class ball
• 6Rows of stitching joining the two halves
• 155.9Minimum weight of a men's ball, in grams
• 22.9Maximum circumference, in centimetres

The dimensions are those set by Law 4 for men's senior cricket. The counts describe a standard first-class four-piece ball.

Why four pieces of leather and not two

You cannot wrap a sphere in flat material without cheating somewhere. Anyone who has gift-wrapped a football knows this. Leather can be stretched and moulded, but only so far, and every millimetre of stretch is a millimetre of uneven thickness in the finished cover.

Cut a hemisphere from a single disc of hide and the material at the edges has to travel a long way to meet at the pole. It thins, it distorts, and it holds the memory of that distortion. Cut the same hemisphere from two quarter-panels instead and each piece only has to curve in one direction, so the stretch is halved and the thickness stays even.

That is why a serious cricket ball is a four-piece ball. Two quarters make each hemisphere, joined by a seam running from pole to pole. Two hemispheres make the ball, joined at the equator by the seam everybody means when they say "the seam".

So a four-piece ball actually has three seams, not one, and only one of them matters to the bowler. The two quarter seams run at right angles to the main seam, one on each half. They are stitched from the inside and hammered flat, so they sit flush with the leather and do nothing to the airflow. If you look closely at a ball on a boundary rope replay you can see them: two faint lines crossing the shiny face, doing nothing at all.

Two-piece balls exist and are perfectly legal in the grades that use them. Each half is moulded from a single piece, there are no quarter seams, and the ball is cheaper and quicker to make. They are used in club and practice cricket in some countries, and they behave differently: the cover is less even, the ball goes soft sooner, and the seam sits on a cover that was stretched harder to get there. First-class cricket uses four pieces because the extra work buys a rounder, more even, longer-lived object, and because a ball that keeps its shape is worth more than a ball that was cheap.

The hide itself is cowhide, alum-tanned, cut from the parts of the skin with the most consistent grain. Thickness is checked and matched, because two quarters of noticeably different thickness will wear at different rates and the ball will develop an asymmetry the maker did not intend. Panels are cut, dyed, moulded into cups under pressure, and left to hold that shape before anything is stitched.

1. 1The cork is ground and compressedCork is broken down and pressed into a small dense sphere. Some makers bond rubber into the mix at this stage to control how lively the finished ball is.
2. 2The core is built upFurther layers of cork are pressed and glued around the centre until the core is the right size and, more importantly, the same density in every direction.
3. 3The quilt is woundThe core is clamped and wound with layers of worsted yarn under high tension. This sets the hardness and most of the weight, and it is the step that decides how long the ball stays round.
4. 4The hide is tanned, dyed and cutCowhide is tanned, coloured and cut into quarter panels. Thickness is matched panel to panel, because uneven leather wears unevenly.
5. 5The quarters are moulded and joinedTwo panels are pressed into a cup shape and stitched together along a quarter seam, which is then hammered flat so it sits flush with the surface.
6. 6The two halves are closed around the coreThe wound core goes inside, and the halves are drawn together and stitched with linen thread in six rows around the circumference. On a hand-stitched ball this is the slow part.
7. 7The ball is pressed and finishedThe finished ball is pressed to true it up, then lacquered, polished and stamped with the maker's mark and the grade.
8. 8The ball is weighed and gaugedWeight, circumference and roundness are checked against the legal band. Anything outside it is downgraded or rejected, which is where most of a maker's yield is lost.

The order is fixed by the physics of the object. You cannot lacquer before stitching, and you cannot stitch before the cover has been moulded to shape.

The seam is six rows of stitching, and the thread does the work

The main seam is where the two hemispheres meet, and it is closed with six rows of stitching in linen thread. Six is the standard for a first-class ball and it is not arbitrary. Fewer rows and the join is weaker and the ridge is lower. More rows and the ridge becomes so wide that it stops behaving like a trip edge and starts behaving like a band.

What matters aerodynamically is not that the halves are joined. It is that the joining leaves a ridge standing proud of the leather. That ridge is the only part of a cricket ball that is deliberately not smooth, and everything a seam or swing bowler does depends on it being there.

Three things set how proud the seam stands. The thickness of the thread, the tension it is pulled to, and how much leather is gathered on either side of it. Thicker thread makes a taller ridge. Higher tension pulls the leather up into a sharper edge rather than letting it slump. And the way the panels are cut at the join decides whether the leather rolls away from the stitching or stands up alongside it.

Thread also has to survive. Linen is used because it is strong, holds a knot, and does not stretch much when wet. A seam thread that stretched would let the ridge collapse the first time the ball got damp, which is a fair description of what a cheap ball does.

How a cricket ball is made to last, or not: hand against machine

This is the single biggest fork in the road, and it explains more about international cricket than any other manufacturing detail.

A machine can stitch a seam quickly, evenly and cheaply. What it cannot do is pull each stitch as hard as a person with a needle and a waxed thread and a lifetime of doing it. Hand-stitching produces higher tension, and higher tension produces a taller ridge that resists being flattened.

Flattening is what actually kills a seam. Every time the ball is struck, every time it pitches, every time it hits the boundary boards, a little of that ridge is pressed back down towards the leather. A hand-stitched seam starts taller and gives ground more slowly. A machine-stitched one starts lower and surrenders faster.

The consequence is a difference in the shape of an innings rather than a difference in quality. Both balls are legal, both are round, both weigh the same. One of them offers a bowler something in the fortieth over and the other does not.

Hand-stitching is also slower, which is the whole reason machine-stitching exists. A ball whose six rows are all done by hand takes a skilled person a meaningful part of a working day once the surrounding stages are counted, and there are not many of those people. That labour cost is why the hand-stitched ball is the expensive one and why the number of hand-stitched rows is a commercial decision as much as a cricketing one.

There is a durability twist that gets missed. Hand-stitching is more resistant to being flattened, but a hand-stitched seam is also more exposed, because it stands higher and takes more of the impact. A proud seam is a seam that gets hit. That is part of why the balls with the most pronounced seams are also the ones that most visibly fray around the stitching late in an innings, with the thread standing away from the leather in strands. The ridge lasts, but it lasts in an increasingly ragged form.

The lacquer and the dye are two different things, and only one of them lasts

The colour and the shine are separate systems, and confusing them is why people misread how a ball ages.

Dye goes into the leather. A red ball is coloured with a penetrating dye at the tannery, so the colour is in the material rather than on it. Wear the surface and the leather underneath is still red. That is why a red ball that has been in play for sixty overs looks battered and scuffed but is unmistakably still red.

Lacquer goes on top. It is a hard nitrocellulose coating applied at the end, and it does two jobs: it seals the leather against moisture, and it provides the gloss that a fielding side spends the first hour of an innings trying to preserve. Lacquer is a consumable. It comes off against the square, the outfield, the bat and the boundary, and once it is gone the fielding side is polishing the leather itself rather than the coating.

How much lacquer a maker applies is therefore a lever on the whole shape of the game. A heavy coat keeps the ball glossy and waterproof for longer, delays the point at which the leather starts absorbing sweat and softening, and extends the window in which conventional swing is available. A light coat gives a ball that is playable in a more traditional way sooner: rougher earlier, softer earlier, and available to the old-ball skills earlier.

There is also a hardness effect. Lacquer stiffens the outermost layer, so a heavily lacquered ball feels harder in the hand for its first thirty overs than the same ball with a thin coat, independent of anything happening in the quilt underneath.

The stamp goes on last, usually gold foil pressed into the leather beside the seam, carrying the maker's name and the grade. It is not decoration. Umpires and groundstaff use it to identify which ball is which when a box of replacements comes out, and it is the first thing to wear off, which is why a well-used ball on television is often unidentifiable.

Grading: two balls off the same bench are not the same ball

Natural materials do not arrive in uniform quality, and this is the fact that governs everything about how balls are sorted.

Hide varies. One part of a skin is thicker than another, has different grain, different scarring, different stretch. Cork varies. Yarn is consistent, but the winding of it is done to a tolerance rather than to an absolute. So a run of balls made to the same specification by the same people on the same day will come off the bench with a spread of properties, and the maker's job at that point is to sort them.

Grading is that sort. The best hides, the most even panels and the balls that land closest to target on weight and roundness go into the top grade, which is what first-class and international cricket uses. Below that sit grades for the levels of the game that cannot pay top-grade prices, made to the same design with less selective materials and, in the cheaper tiers, fewer hand-stitched rows or a two-piece cover.

Two consequences follow.

The first is that a grade is a statement about consistency, not only about performance. What a first-class competition is buying is a box of balls that behave the same as each other, so that a match is not decided by which ball came out of the box. A club buying a lower grade is accepting a wider spread.

The second is that grading is where a maker's yield lives, and yield is where quality problems show up first. If the hides coming in are less consistent than usual, the top grade does not get worse so much as it gets smaller, and the pressure to fill orders pushes balls into it that would previously have been sorted downwards. That is the mechanism behind almost every complaint about ball quality in the professional game, and we will come back to it.

• Minimum
• Maximum

Men's ball155.9g163g

Women's ball140g151g

Under-13 ball133g144g

Law 4 sets a different weight range for men's, women's and junior cricket. Every legal new ball sits somewhere between the two figures for its category.

Show the numbers

The weight band Law 4 allows, by grade of cricket

Item	Minimum	Maximum
Men's ball	155.9g	163g
Women's ball	140g	151g
Under-13 ball	133g	144g

What actually differs between a Dukes, an SG and a Kookaburra

All three are four-piece leather balls of legal weight and size. The differences are in the stitching, the finish and the hide, and they are small differences with large consequences.

The Dukes, used in England and the West Indies, has all six rows of its main seam stitched by hand and carries a heavy lacquer. That combination gives a ball that keeps a proud seam and a hard glossy surface deep into an innings. English conditions get described as swing-friendly as though the weather were doing all of it. A great deal of it is the ball, and specifically the fact that the seam is still standing at the point where other balls have gone flat.

The SG, used in India, is hand-stitched with notably thick thread and has the most pronounced seam of the three. Its lacquer disappears quickly, especially on a dry, abrasive square. That produces an unusual pairing: a rough surface early, which favours the old-ball skills, alongside a seam that is still tall enough to grip the pitch and to hold an angle in the air.

The Kookaburra, used across most of the rest of the world, has only two of its six rows stitched by hand and the remaining four done by machine. The seam flattens sooner. The familiar consequence is the Kookaburra innings shape: a genuine but short window at the start, a long flat middle in which the ball offers very little, and whatever the ground's abrasiveness can give a bowler after that.

None of the three is better. They are three different answers to the same question about how long a ball should stay interesting, and each was designed around the cricket played where it is made. The reason the differences feel so large is that a bowler's whole method is built around what the ball is doing, and a bowler who has spent a career with one ball has to relearn the timing of an innings with another. It is also why judging anyone's away record without asking which ball they were holding is a poor way to read a career, whatever the numbers on our player pages say in isolation.

The thing all three share is that the manufacturing decisions are visible in the first hour and decisive in the fourth. The seam is doing the work, and it is doing it with whatever height the stitching left it.

Why the pink ball had to be built differently

Pink is not a red ball in a different colour. It is a genuine engineering problem, and the solution changed the object.

The difficulty is that the way a red ball gets its colour does not work for pink. Red dye penetrates hide well and stays red as the surface wears. Pink does not penetrate the same way, and the treatments that make leather supple and durable also darken it, so a pink achieved in the drum comes out muddier than it went in and then fades towards brown under wear. A ball that is only pink for twenty overs is no use in a session played under floodlights.

So pink balls are finished with pigment on the surface rather than relying on dye alone, sealed under extra lacquer. That solves visibility and creates two side effects that anyone watching a day-night Test has seen.

The first is that pigment covers the grain of the leather. Shining a red ball works partly because polishing lays down the grain and works the wax into it. A pigmented surface is already a coating, and fielders report that it takes far more effort to raise a shine on one. Maintaining a pink ball is harder work for less reward.

The second is that the extra lacquer keeps the ball hard and glossy for longer, which delays the point at which it roughens. A ball that will not go rough will not do the things a rough ball does, so the twilight session tends to be about conventional movement and lateral seam rather than the old-ball repertoire, and the middle overs of a pink-ball innings look different from the middle overs of a red-ball one. The seam is often stitched in black thread rather than white, because a white seam on a pink ball is harder to pick up under lights than a dark one.

Then there is the way a pink ball ages. A red ball's lacquer wears off and reveals red leather. A pink ball's pigment wears off and reveals whatever pale base the hide was before it was coated. The ball does not so much get scuffed as go patchy, and the patches are lighter than the ball rather than darker. The full picture of how that plays out across a session is a subject of its own in our piece on what the pink ball actually changes about a Test.

The white ball, and the reason it is replaced so often

White balls are pigmented too, for the same reason and with the same consequence: the colour sits on the surface, and once the surface is scuffed the ball turns grey and green from grass stains and dirt at a rate a red ball never does.

That is a visibility problem rather than a performance one, and it is why the limited-overs formats have spent years adjusting how many balls are used and when. Using two new balls from opposite ends keeps each of them younger and whiter, at the cost of never letting either get old enough to do anything interesting. Using one ball for a whole innings gives you a genuinely old ball in the last ten overs and a ball nobody can see.

That trade has moved recently and in an instructive direction. The men's one-day international playing conditions were changed in 2025 so that the two new balls are used only for the first part of the innings, after which the fielding side picks one of them to use for the remainder. The reasoning was explicit: two permanently youngish balls had removed reverse swing from the format, and the change was made to give the older ball a chance to matter again. It is a rule written entirely around a manufacturing fact, which is that a pigmented white ball cannot be allowed to get as old as a red one without becoming invisible.

The white ball also softens faster in practice, because limited-overs cricket is played on flatter surfaces and the ball is hit harder and more often. A soft ball skids rather than bounces and comes off the bat more slowly, which is a good part of why the last ten overs of an innings and the first ten look like different sports.

What the Laws fix, and what they leave to the maker

Law 4 is shorter than most people expect, and the gaps in it are deliberate.

The Law fixes the weight and the circumference. For men's senior cricket a new ball must weigh between 155.9 and 163 grams, and its circumference must fall between 22.4 and 22.9 centimetres. Women's cricket and junior cricket have their own bands, both lower and smaller. Umpires carry a ring gauge to check the size, which is the small metal hoop you occasionally see one of them holding a ball up against.

The Law also fixes the process around the ball rather than the object. Each innings starts with a new ball. In a match of more than one day's duration, the fielding captain may take a new one after a minimum number of overs, which is eighty in a Test. Only one ball is used at a time unless it is lost or becomes unfit for play.

What the Law does not fix is almost everything discussed above. It says nothing about how many pieces the cover has, how many rows of stitching hold it together, how many of those are done by hand, what the core is made of, how tightly it is wound, or how much lacquer goes on. Those are matters for the competition, which approves a make of ball, and for the maker, which builds it.

That is a sensible division and it is worth understanding why. A Law that specified construction would freeze the ball at whatever the technology of the day allowed and would make every manufacturing improvement illegal until the Law was rewritten. A Law that specifies weight and size and then leaves the rest to approval lets competitions choose the ball that suits their cricket. The cost is exactly what the game has: a sport in which the equipment differs meaningfully by country and nobody quite agrees on whether that is a feature. The broader set of rules that decide more matches than most spectators notice is collected in our guide to the laws worth actually knowing.

When a ball may be replaced, and who gets to choose

Replacement is the part of Law 4 that comes up most and is understood least, usually at the moment a bowler has been asking for a new one for twenty minutes.

A ball may be replaced when it is lost, or when the umpires judge it unfit for play. Unfit means out of shape, or damaged in a way that makes it unsuitable, and the judgement belongs to the umpires and to nobody else. A captain may ask. The umpires decide.

The replacement is not new. It is a ball of comparable wear, chosen from a box that the umpires keep for the purpose, and the crucial point is that the umpires select it rather than the fielding side. That single detail removes almost all the incentive to engineer a replacement, because a side that ruins a ball does not get to pick what it gets instead.

1. 1Someone raises itUsually the bowling side, occasionally the batters, sometimes the umpires themselves at a routine inspection between overs.
2. 2The umpires examine itBoth of them, together. Shape is checked against a ring gauge; wear and damage are judged by eye and by hand.
3. 3They decide whether it is fitIf the ball still passes, play continues and the answer is no, however loudly it is asked again next over.
4. 4A box of replacements is brought outIt holds balls of varying age, kept for exactly this purpose. The used ones have often been worn deliberately in the nets so that a match-age replacement exists.
5. 5The umpires choose the replacementThey pick the ball closest in wear to the one being replaced. The fielding captain does not choose, which is the whole reason the system works.
6. 6The batters are informedThe change is announced so that the batting side knows what it is facing, and the game restarts from the same over.
7. 7The over count carries onA replacement is not a new ball in the sense of Law 4. The count towards the second new ball keeps running from where it was, so a side that has a ball changed in the sixtieth over does not get a fresh eighty.

The procedure is the same whether the ball is lost, has gone out of shape, or has been found to have had its condition unfairly altered. What differs is only whether penalty runs follow.

The final step is the one that surprises people. Having a ball replaced does not reset the clock. The entitlement to a genuinely new ball still arrives when the over count says it does, which is why a captain will sometimes decline to make a fuss about a scuffed ball at over seventy and simply wait ten overs for the real thing. The tactics around that decision, and around when to take the new ball once it is available, are worth their own explanation.

Where the umpires judge that the condition of the ball has been changed unfairly rather than merely worn, the same replacement procedure runs and penalty runs are added on top. The replacement in that case is doing double duty: it restores a fair ball and it removes the prize.

How construction decides what the ball does in the air

Everything in this piece converges on two surfaces and one ridge.

The ridge is the seam, and how tall it stands is a function of thread thickness, stitching tension and how many rows were done by hand. A tall seam trips the airflow and grips the pitch. A flattened one does neither.

The two surfaces are the halves either side of that ridge, and what matters is the difference between them rather than the state of either. One face is polished and defended from the first over; the other is left alone. How quickly that gap opens depends on how much lacquer the maker applied and how abrasive the ground is. How much the gap is worth depends on how rough the rough side gets.

Those are the inputs to swing, and the mechanism itself, both the conventional kind and the reversal that arrives when the ball is old, is set out in full in our piece on why an old ball moves the other way. What is worth carrying across from here is that none of it is available to a bowler by choice. A bowler with a machine-stitched ball on a lush outfield cannot decide to have a proud seam and a rough face. The manufacturing decided it, the grounds staff decided the rest, and the bowler's skill is entirely a matter of what he can do with what he has been handed.

Movement off the pitch has the same dependency, in a more direct way. Seam movement happens when the raised stitching lands on the surface and grips unevenly, so a ball with no ridge left cannot seam regardless of what the pitch is offering. The surfaces that reward it, and the ones that do not, are covered in our guide to what different pitch types actually do.

What changed recently, and why 2025 was awkward for Dukes

Ball manufacturing is not a static industry, and the most visible reminder of that in recent years came during the 2025 Test series between England and India, when the Dukes ball repeatedly went out of shape long before eighty overs and had to be changed. Players on both sides complained publicly, umpires reached for the gauge more often than usual, and the argument ran for most of the summer.

The manufacturer, British Cricket Balls Ltd, said it would review the whole process, from the tanner and the raw hides through to assembly. The explanations offered pointed at the supply chain rather than the design: changes in tanning chemistry, variation in the hides available, and a shortage of people with the skills the process depends on.

That is a more interesting story than a simple quality complaint, because it shows exactly where a hand-made object built from natural materials is fragile. The design of the ball had not changed. What changed was the consistency of what was going into it, and consistency is the entire proposition of a top-grade ball. A run of hides that tan slightly differently produces covers that stretch slightly differently, and a ball whose cover is not evenly matched to the quilt underneath will lose its shape earlier under exactly the same treatment.

It also shows why grading matters so much. A maker under pressure to fill an order from a less consistent batch of raw material has to either ship fewer balls or lower the bar, and the second option is invisible until somebody is holding the ball in a Test match. Nothing about that is unique to one manufacturer. It is the standing risk in an object that is still, in the parts that matter, made by hand.

The other recent change worth knowing is the one-day international ball rule described above, which took effect in 2025 and was explicitly aimed at putting an older ball back into the second half of an innings. Both stories are about the same thing from opposite directions: the professional game constantly adjusting itself around what a leather ball does as it ages.

How to read a ball from the stands

You can learn a surprising amount about what is about to happen from the object itself, if you know what to look at.

Look at the seam edge on, not face on. A ball with a proud seam casts a visible line of shadow along the stitching in a replay. A flattened one does not. That is the single best predictor of whether anything is going to happen in the air.

Look for the quarter seams. Two faint lines crossing the polished face at right angles to the main seam tell you it is a four-piece ball. Their absence tells you it is a two-piece, which in most cricket you will watch means you are at a level below first-class.

Watch the colour rather than the gloss. A red ball that is scuffed but still red is worn on the surface only. A ball going brown and blotchy has lost its lacquer and started absorbing moisture, which means it is also going soft. On a white or pink ball, watch for patchiness, because that is pigment coming off rather than dirt going on.

Count the hands on it. A fielding side that is serious about the state of the ball restricts it to two or three players, throws it back on the full, and keeps it out of wet grass. A ball being handled by everybody is a ball nobody has a plan for.

Watch the umpires. More inspections than usual means the shape is in question, and a box coming out means somebody has decided the answer.

And when the new one is taken, look at it in the first over. A brand new ball at the top of its grade is a genuinely beautiful object: perfectly round, deeply coloured, glossy enough to reflect the floodlights, with a ridge you can see from the boundary. That is the state the whole manufacturing process is aiming at, and it lasts about half an hour. Everything after that is the ball ageing, which is the part of cricket that the equipment, rather than the players, actually writes.

More on the equipment, the laws and the skills that hang off them is collected across our cricket coverage, including the companion piece on how a bat is put together, which turns out to be a story about a completely different material behaving in a completely different way.