The TEX thread designation system indicates the linear weight (in grams per 1,000 meters of thread). The higher the TEX number, the stronger the thread.
TEX (tex) = weight (g) of a single thread with a length of 1,000 m
dtex (dtex) = weight (g) of a single thread with a length of 10,000 m
A thread that is made of multiple threads is designated by the TEX number x the number of threads. For example, a TEX 14x2 thread is made of two threads, each with a TEX of 14.
| TEX | Thread thickness | Use |
| 16 - 21 | very thin | silk, fine curtains, very light fabrics |
| 24 - 30 | thin | shirting, blouses, light cotton fabrics |
| 30 - 40 | middle (universal) | everyday clothes, bedding, knitwear |
| 60 - 80 | stronger | denim, workwear, stronger fabrics |
| 100 - 120 | very strong | quilting denim, heavy fabrics, leather |
| 200+ | extremely strong | technical fabrics, upholstery, tents, leather |
