A tex unit is equal to the weight in grams of 1,000 meters of fiber. Therefore, the strength reported is the force in grams required to break a bundle of fibers one tex unit in size. Leaf refers to small particles of the cotton plant's leaf that remain in the lint through the ginning process. Leaf desiccation due to harsh defoliation or frost damage can lead to higher, less profitable leaf grades. Extraneous matter is any substance in the cotton other than fiber or leaf.
Examples are bark, grass, spindle twist, seed coat fragments, dust, and oil.
The amount of extraneous matter is reported as level 1 or level 2, with level 2 indicating heavier contamination. Classers also identify special-condition cotton. Some of these conditions cause processing problems and reduce yarn quality. The HVI color measurements cover grayness and yellowness. The Nickerson-Hunter cotton colorimeter color diagram on page 11 of Cotton Classification Results is based on current official standards for American Upland cotton and shows how these measurements are coded and how they relate to the color of the grade standards.