he most common weight system specifies the length of the thread in kilometres required to weigh 1 kilogram. Therefore, a greater weight number (indicated in the American standard by the abbreviation wt) indicates a thinner, finer thread. The American standard of thread weight was adopted from the Gunze Count standard of Japan which uses two numbers separated by a forward slash. The first number corresponds to the wt number of the thread and the second number indicates how many strands of fiber were used to compose the finished thread. It is common to wrap three strands of the same weight to make one thread, though this is not a formal requirement in the US standard (which is therefore less informative).
|Weight||Gunze Count||Common Use|
|Light||60 wt||#60/3||bobbin or appliqué|
|Thin||50 wt||#50/3||bobbin or appliqué|
A denier weight specification states how many grams 9,000 meters of the thread weighs. Unlike the common thread weight system, the greater the denier number, the thicker the thread. The denier weight system, like the common weight system, also specifies the number of strands of the specified weight which were wrapped together to make the finished thread.
Tex is the mass in grams of 1,000 meters of thread. If 1,000 meters weighs 25 grams, it is a tex 25. Larger tex numbers are heavier threads. Tex is used more commonly in Europe and Canada.
Some thread manufacturers, especially those producing very fine silk threads, apply their own scales of thread measurement using "aughts" or zeroes (not unlike the zeros used in measuring the sizes of seed beads). Within a given manufacturer's spectrum, a higher "aught count" indicates a finer thread: this is usually given as a single digit followed by a forward slash and a zero— for example, 3/0 indicates a three-aught thread or a thread size "000", but this number only has significance when compared to other threads produced by the same manufacturer: one manufacturer's 4/0 will always be more fine than that same manufacturer's 2/0, but will mean nothing if compared to the 4/0 of another manufacturer. The aught scale therefore is not suitable for conversion or comparison to other more-generalized weight scales, though it is in common use.