How Is Cotton Thread Weighed?

Cotton thread may be weighed using many different systems.

Cotton thread is normally sized by weight, but several different systems are in use. Possible options include modern systems such as the metric and Tex systems and older methods such as cotton count. This can make choosing the right thread for a given project difficult and confusing. Understanding the different systems for describing cotton weight can help crafters find the correct supplies for their projects.

Significance

Cotton thread is sized by weight because spinning mills purchase fiber by this measurement, according to Fashion Incubator. Measuring the diameter of a thread is difficult, especially without computer technology. All thread sizing systems measure the amount of thread that can be produced from a given weight of cotton fiber.

Cotton Count

The cotton count system, also called the yarn size system, measures the number of 840-yard threads that can be produced from 1 pound of fiber. Higher numbers indicate a thinner thread. When the thread is plied—twisted from two or more smaller threads—the number of plies is added to the yarn size. So, a thread made from two size 40 yarns would be expressed as 40/2 and would contain the same amount of fiber as a single size 20 yarn. In the Hong Kong ticket system, the number is the same but no slash is used—the same thread would be expressed as 402.

Tex

The most common modern system, Tex measures the weight in grams of a piece of thread one kilometer long. Higher numbers indicate a heavier thread in this system. The thread size may be expressed as Tex 40 or T-40. However, the actual thread may be within 10 grams of its rating, since thread size is rounded to the nearest 10 in this system.

Metric Count

Thread weighed by the metric count system measures the number of 1 kilometer threads in 1 kilogram of fiber. This is roughly equivalent to 1,000 divided by the thread's Tex number. As in cotton count, higher numbers indicate a finer thread and lower numbers a heavier one. This system may also be expressed with the ply, so it's not possible to assume that a number like 70/3 is either metric or cotton count, just from its appearance. The related metric ticket system gives the metric count for a three ply thread the same weight as the thread being measured, or three times the metric count of the thread.

Denier

Rarely, cotton thread may also be measured using the Denier system, though this system is more commonly used for nylon. This system numbers thread based on the weight in grams of a thread 9 kilometers in length. Higher numbers indicate a heavier yarn. Threads figured in Denier are usually written with a d after the number. For instance, luggage-weight fabric woven from heavy thread might be listed as 1000d.

References

• Fashion Incubator: Thread sizes