Tex

Definition and Overview

Tex is a yarn thickness unit that expresses mass in grams per 1,000 meters of length. For example, 1 tex means 1 gram per 1,000 meters of yarn. The greater the mass for the same length, the larger the tex value.

It is used to manage yarn thickness under a common standard and is checked in specifications for woven yarns, knitted yarns, and sewing threads. It is a separate item from the material name, twist, and whether the yarn is single yarn or plied yarn, so the overall properties of the yarn cannot be determined by tex alone.

Characteristics and Effect on Fabric

In general, yarn with a higher tex is thicker, and if the structure and density are the same, it tends to give the fabric more thickness, weight, and presence. Thick yarn can make the weave or knit structure more visible, which may create a casual and strong appearance.

On the other hand, yarn with a lower tex is finer and tends to create a delicate, smooth surface in fine-count fabrics. However, hand feel, sheerness, strength, and warmth retention are also affected by fiber type, twist, density, structure, and finishing, so they are not compared by tex value alone.

Main Applications

Tex is used to indicate specifications for a wide range of yarns, including warp and weft yarns that make up fabric, yarn for knits, and sewing thread. Fine yarn may be used for lightweight shirting or lining, while thicker yarn may be used for denim, canvas, workwear, and bag fabrics.

Season and item are not determined by tex alone. Even for summer items, appropriate firmness may be added through high density or finishing, and for winter items, a lightweight yarn setup may be chosen. In planning, it is important to check tex together with fabric weight, density, and structure.

Selection and Handling Notes

When selecting fabric or sewing thread, check not only the tex value but also the material, single yarn or plied yarn, twist, tensile strength, and elongation. In sewing, if the thread is too thick for the fabric, seam unevenness and puckering may become noticeable; if it is too fine, seam strength may be insufficient.

Shrinkage and dimensional change after washing are not determined by tex itself. Testing or wash verification should be performed including the fiber's water absorption, thermal shrinkage, woven or knitted density, and finishing. For fabrics made with thick yarn, trial sewing is recommended, including selection of the needle and sewing thread.

• Check whether the stated tex value is for single yarn or for yarn after twisting together.
• Check the tex of the warp and weft, or the face yarn and back yarn, separately.
• Compare fabric thickness and durability together with fabric weight and density.
• Before mass production, confirm shrinkage, seam appearance, and seam strength with wash testing and trial sewing.

Differences from Similar Terms

Denier is also a constant-mass unit that expresses yarn thickness by mass per length, but the standard length differs. Tex is expressed as grams per 1,000 meters, while denier is expressed as grams per 9,000 meters. Be careful not to treat the numerical values as directly equivalent.

Count is another way to indicate yarn thickness, but depending on the system, such as cotton count or metric count, a larger number may mean a finer yarn. With tex, a larger number means a thicker yarn, so it is necessary not to confuse it with count notation. Decitex is one-tenth of a tex.

Frequently Asked Questions