| Jacob's fleece | The natural brown shade of the Jacob's sheep. |
| Jacob's fleece | The natural brown shade of the Jacob's sheep. |
| Jacquard | "A description of techniques used for knitting and weaving to obtain large-scale and/or figured designs (named after the inventor, Joseph Marie Jacquard, 1752-1834)." |
| Jacquard Knit | "A weft double knit fabric in which a Jacquard type of mechanism is used. This device individually controls needles or small groups of needles, and allows very complex and highly patterned knits to be created." |
| Jaspé | A fabric characterised by a subtle striped effect. |
| Javanese | "A viscose cloth with a spun weft and filament warp, characterised by a dull sheen." |
| Jersey fabric | A generic name applied to weft knitted fabric. |
| Jersey stitch | "A basic stitch used in weft knitting, in which each loop formed in the knit is identical. The jersey stitch is also called the plain, felt, or stockinet stitch." |
| Joint venture | "A joint undertaking of a new, usually risky business in, for example, a developing country or in Eastern Europe." |
| Judo | A structured cloth constructed in varieties of piqué weave and usually made in cotton. |
| Jute | A fibre obtained from the bast layer of the plants Corchorus capsularis and Corchorus olitorius. |