Twist per inch

[2] Twist is needed in yarn to hold the fibres together, and is added in the spinning and plying processes.

The amount of twist also affects the yarn in terms of stretchiness, strength, halo, and many other attributes.

Measuring the number of twists per inch while spinning singles also helps the spinner create a balanced yarn when plying.

Another method is to measure an inch of yarn and untwist it, counting how many full revolutions it takes until there is no twist left.

This can be done by inserting two paper-clips into the yarn, at an inch apart, thus making it easier to count a full revolution.

[2] Thus one can roughly find the number of twists per inch for the single, or one can use the doubled back yarn as a measure.

This Twist Multiplier is an empirical parameter that has been established by experiments and practice that the maximum strength of a yarn is obtained for a definite value of K. In the case of ring spun cotton yarns, for example, the following values of K have been found to give the best results.