Single jersey is knitted on one needle bed, while interlock is knitted on two, which gives a thicker, firmer fabric that looks the same on both sides. Jersey has V-stitches on the face and a different back, stretches more and curls at the edges. Interlock lies flat when cut, looks smooth on both sides and distorts less.
With the same yarn, interlock is usually heavier and more opaque. Choose jersey for lightness and stretch, interlock for stability and a clean look on both sides.
single jerseyinterlockcomparison
