Interlock fabrics are knitted on two needle beds in which the needles are directly opposed and work alternately. Both sides of the fabric look identical and have a close surface structure. Interlocks are extensible, but not as much as for example rib fabrics. One of the good things about interlocks is that they don't curl, which makes them easier to work with. They have many different applications: underwear, sports, leisure wear and T-shirts.