A purl is a type of stitch used in knitting. It is essentially the reverse of a knit stitch, where the yarn is looped through the stitch from front to back.
Purl stitches are the building blocks of many knitted fabrics. When combined with knit stitches in various patterns, they form complex textures and shapes. The term 'purl' is therefore directly associated with the creation of knitted structures.
Considering the options, a purl is most accurately described as a component fundamental to a knitted structure.
A circular weft knitting machine with 24 inch gauge and 20 inch diameter needle bed is used to make a tubular knitted fabric. If the fabric shrinks by 35 % in course-wise direction upon withdrawal from the machine, the circumference (inch) of the shrunk tubular fabric is approximately
Group I gives a list of terms related to woven fabrics and Group II contains equivalent terms related to knitted fabrics. Match the term from Group I with the equivalent term from Group II.
| Group I | Group II |
| P. Cover | 1. Interlock |
| Q. Double-cloth | 2. Wales |
| R. Warp | 3. Tightness |
| S. Weft | 4. Courses |
The wale constant and course constant are 4.2 and 5.04 respectively. If the loop length is 4.2 mm, then stitch density (number/cm$^2$) is______.