Oh, I learned something new today... I never knew what "dtex" meant when it comes to fabric. Someone just informed me earlier this afternoon. :)

It's actually a short term for "decitex" and has the same meaning as "Denier".
Decitex or dtex = the unit of measurement of linear density of a continuous filament or yarn.

In the past, I only knew that ladies stockings (skin socks) were classified according to their Denier, i.e. 50 Denier, 80 Denier, etc... All I knew was that the higher the Denier value, the thicker was the socks (less transparent)... Hehehe...
Come to think of it, I've actually come across "Denier" during my college days, but never heard of "dtex"...or did I not pay proper attention??? Hahaha... something for me to ponder on. :D