Single jersey, interlock and rib explained
Short answer: The three terms describe how the fabric is knitted. Single jersey is thin and curls at the edge, interlock is thicker and does not curl, and rib is the stretchiest of the three.
Single jersey
Single jersey is the most common knit for t-shirts. The fabric is light, with a smooth face of small vertical stitches and a back of horizontal loops. The edge curls if it is not hemmed or folded, because the two sides pull differently.
Interlock
Interlock is two layers of jersey knitted together into one fabric. This makes it thicker and the same on both sides, so there is no clear face and back. The edge does not curl, and the fabric feels firmer and more stable in the hand than single jersey.
Rib
Rib is knitted with vertical ridges, where stitches on the face and back alternate in a fixed pattern. That makes the fabric very stretchy across its width, and it recovers well. Rib is often used for neck, sleeve and waist trims, but also for whole tops.
Where they are used
Single jersey is typically used for t-shirts and light tops, interlock for firmer underwear and rib for trims and close fitting tops. Many garments combine two of them, such as a single jersey t-shirt with a rib neckband. See bamboo undershirts for men.
What you can feel
Interlock feels firmer and slightly heavier, single jersey lighter and airier. Rib feels elastic and close fitting. All three can be comfortable against the skin, but they serve different purposes. It is often the knit rather than the fibre that decides how clothes feel.
The edge tells you
If the edge of a top or a piece of fabric curls, it is almost always single jersey. That is neither good nor bad, but it explains the behaviour. That is why most t-shirt edges are hemmed or finished with a rib trim, so they lie flat.
For underwear
Underwear often uses a firmer knit, because it needs to lie flat and not curl when worn close to the body. A firm knit also covers better and keeps its shape longer. See the styles in bamboo underwear for women, where the knit is chosen to suit the use.
Washing and care
All three knits can be washed the same way, at 30 to 40 degrees with a moderate spin. Single jersey can twist slightly if dried incorrectly, so pull it gently into shape before hanging it up. Rib should not be stretched while wet, as it can lose some recovery.
Which to choose
If you want something light and cool for summer or as an inner layer, single jersey is a good choice. If you want something that sits firmly and does not curl, interlock is better. If clothes should fit closely and follow the body, rib is the stretchiest.
Read more
If you want to know more about the fabric behind most of our t-shirts and much of our underwear, and how it behaves in wear and in the wash, read bamboo jersey. The fibre and the knit are explained in more detail there.
Frequently asked questions
Why does the edge of my t-shirt curl
Because it is knitted in single jersey, where the face and back pull differently. That is normal, which is why most edges are hemmed or finished with a rib trim.
What is the difference between jersey and interlock
Single jersey is one layer of knitted fabric with a clear face and back. Interlock is two layers knitted together, so the fabric is thicker, firmer and the same on both sides.
What is rib used for
Rib is mostly used for neck, sleeve and waist trims, because it stretches well and pulls back again. It is also used for close fitting tops and jumpers.
You can find the full range at Bamboo-Clothing.com.
