Last updated: by Thanassis Koukoutselos
Short answer: a basketball is made of four layers: a butyl rubber bladder that holds the air, a layer of nylon and polyester windings that keeps the ball round, a rubber carcass that gives it bounce, and an outer cover of leather, composite (synthetic) leather or rubber. The cover is what you feel, and it decides where the ball should be used: leather indoors only, composite indoors and out, rubber mainly outdoors.
The 3 cover materials compared
| Cover | Made of | Best for | Feel and durability | Example |
|---|---|---|---|---|
| Genuine leather | Cowhide (steer hide), tanned and pebbled | Indoor games only | Best grip and feel once broken in; scuffs and dries out on asphalt | Molten BG5000 |
| Composite leather | Synthetic microfiber or polyurethane | Indoor, or indoor and outdoor | Good grip from day one, no break-in; the cover of most mid-price indoor balls | Wilson Evolution |
| Rubber | Natural or synthetic rubber | Outdoor courts, kids, beginners | Cheapest and toughest; less grip and a harder feel | Spalding Street Outdoor |
What is inside a basketball?
Using the official NBA ball as an example (Wilson makes it in partnership with Horween Leather Co. in Chicago), a ball is built in four layers from the inside out:
- Bladder: a balloon of mostly butyl rubber with some natural rubber, molded and cured with heat. Butyl is used because it holds air for a long time. The valve you put the needle into is part of the bladder.
- Windings: nylon and polyester thread wound by machine around the inflated bladder, set with a little adhesive. This layer keeps the ball perfectly round and stops it from stretching.
- Carcass: a layer of rubber (a styrene-butadiene and natural rubber mix) molded over the windings. It gives the ball its bounce and forms the raised black channels between the panels.
- Cover: eight panels of leather (or composite, or a molded rubber skin on cheaper balls) glued into the spaces between the channels. Molten’s FIBA balls use a 12-panel layout instead.
So a basketball is not “filled” with anything but air. The inflation pressure keeps all those layers taut; see how much air should be in a basketball.
The valve. The valve is a small plug set into the bladder; the pump needle passes through it and it seals again when the needle comes out. Valves can dry out over time and start leaking air slowly, which is why Spalding recommends dipping the needle in glycerin or water before inserting it (Spalding inflation guide). If a ball still loses air through the valve after that, see our basketball repair guide.
What are NBA basketballs made of?
Genuine leather. The cover of the Wilson NBA ball is made from steer hides, a by-product of the meat industry, tanned by Horween in Chicago, shaved to about 1.4 mm, embossed with the pebbled grip pattern and dyed orange. The color darkens with use.
The NBA did try a synthetic ball once. In the 2006-07 season it replaced the leather ball with a Spalding microfiber composite ball, but after players complained, including about hand injuries, the league switched back to leather on January 1, 2007.
Leather vs composite vs rubber: which should you buy?
- You play indoors in a league: composite leather. It grips well right away and keeps its feel. Leather is only worth it if you will play only indoors and give it time to break in. See our composite leather guide.
- You play outside on asphalt or concrete: rubber, or a tough indoor/outdoor composite. Leather will be ruined in weeks. See our rubber basketball guide.
- You play both: an indoor/outdoor composite ball, or one composite ball for the gym and a cheap rubber ball for the park.
- For kids: rubber, in the right size for their age. Check the basketball size chart.
How basketball materials have changed
When James Naismith invented the game in 1891, players used a soccer ball. The first balls made for basketball had a laced leather cover over a rubber bladder; today’s balls are molded without laces, with nylon windings and, in most cases, a composite cover. More history on our page about the first basketball.
Related guides: types of basketballs, the first basketball.
FAQ
What is a basketball made of?
A butyl rubber bladder, nylon and polyester windings, a rubber carcass and a cover of leather, composite leather or rubber.
Is the NBA ball leather?
Yes. The Wilson NBA official game ball has a genuine leather cover tanned by Horween. The NBA’s one experiment with a synthetic ball, in 2006, was reversed after half a season.
What animal is a leather basketball made from?
Cowhide. The NBA ball uses steer hides that are a by-product of the meat industry.
Are basketballs vegan?
Composite and rubber balls have no leather cover, so they are the choice if you want to avoid animal products; check with the maker if adhesives or other components matter to you. Genuine leather balls are not vegan.
What is inside a basketball?
Air, held in a rubber bladder. There is no foam or liquid inside a regular basketball.
Sources
- Popular Mechanics: How Wilson makes official NBA basketballs
- NBA.com: 2006-07 season review
- Wikipedia: History of basketball
- How to Pass a Basketball (5 effective tips) - August 25, 2022
- Learn How to Spin a Basketball on your Finger in less than 3 minutes - July 18, 2022
- Where Are Basketballs Made? Spalding, Wilson and Molten (2026) - June 10, 2022