What is the difference between single jersey and double jersey knitting machine?

Single jersey knitting machine produces a fabric with a plain, smooth surface and a single layer of interlocking loops. It is used for lightweight fabrics such as t-shirts, underwear, and sportswear. Double jersey knitting machine produces a fabric with a thicker, more substantial feel and two layers of interlocking loops. It is used for heavier fabrics such as sweaters, jackets, and blankets. In addition, double jersey knitting machine has the ability to produce various patterns and designs, while single jersey knitting machine is limited to basic patterns.