Weft knitted fabric structures

Plain, rib, interlock and purl are four primary structures from which all weft knitted fabrics are derived.

Plain is produced by using one set of needles, drawing the loops to only one side of the fabric.

The technical face of plain weft knitted fabric.

The technical back of plain weft knitted fabric.

Rib is produced by using two sets of needles operating in between each other so that wales of face loops and wales of reverse loops are knitted on each side of the fabric. Both face and back of fabric look exactly the same.

Face and reverse loop wales in 1 × 1 rib.
Click to enlarge

1 × 1 rib fabric

Flat weaving machine

6 × 6 rib fabric

Interlock - Originally derived from rib, this structure requires a special arrangement of needles. By knitting back-to-back in an alternate sequence of two sets the two courses of loops show wales of face loops on each side of the fabric exactly in line with each other, thus hiding the appearance of the reverse loops.

Interlock fabric structure

What is typical for the binding: Interlock?

1.   Low stretch out, low contracting back  
2.   High elasticity  
3.   Big risk for felting  
4.   Shrinkage after washing  
5.   Different look on the two sides  

The binding creates space for possibilities of shrinking, and with cotton as a textile material it completes the result.

Purl is the only structure which has certain wales containing both face and reverse meshed loops.

Purl fabric structure