Fabric Labelling Code of Practice

The International Wool Textile Organization has codified fabric quality definitions relating to the use of Super "S" and "S" descriptions, stating:

Pure Wool Fabrics.

The word Super (as in SUPER 100's, for example) can only be used to describe fabrics made from pure new wool, and the "S" value is determined by, and must comply with the Maximum Fibre Diameter values in the following table:

"S" Value
Maximum Fibre Diameter
"S" Value
Maximum Fibre Diameter
SUPER 80's
19.75 m
SUPER 170's
15.25 m
SUPER 90's
19.25 m
SUPER 180's
14.75 m
SUPER 100's
18.75 m
SUPER 190's
14.25 m
SUPER 110's
18.25 m
SUPER 200's
13.75 m
SUPER 120's
17.75 m
SUPER 210's
13.25 m
SUPER 130's
17.25 m
SUPER 220's *
12.75 m
SUPER 140's
16.75 m
SUPER 230's *
12.25 m
SUPER 150's
16.25 m
SUPER 240's *
11.75 m
SUPER 160's
15.75 m
SUPER 250's *
11.25 m

* Proposed description of 220's, 230's, 240's and 250's.

SUPER "S" descriptions can also be used for fabrics made from wool blended with rare fibres (such as mohair, cashmere and alpaca), and also with silk. The inclusion of elasthane to give the fabric a stretch effect is permitted, as also is the inclusion of up to 5% non-wool yarn for decorative effects.

The Test Methods to be used to determine Mean Fibre Diameter values are:
IWTO -8 (PROJECTION MICROSCOPE) or
IWTO - 12 (LASERSCAN)

Wool Blend Fabrics.

For wool blend fabric descriptions, the word Super is not permitted. Subject to the wool content being at least 45%, the "S" value must comply with the following table:

"S" Value
Maximum Fibre Diameter
"S" Value
Maximum Fibre Diameter
80's
19.75 m
170's
15.25 m
90's
19.25 m
180's
14.75 m
100's
18.75 m
190's
14.25 m
110's
18.25 m
200's
13.75 m
120's
17.75 m
210's
13.25 m
130's
17.25 m
220's *
12.75 m
140's
16.75 m
230's *
12.25 m
150's
16.25 m
240's *
11.75 m
160's
15.75 m
250's *
11.25 m

* Proposed description of 220's, 230's, 240's and 250's.

The Test Methods to be used to determine Mean Fibre Diameter values are:
IWTO -8 (PROJECTION MICROSCOPE)