The inherent value of any greasy wool measurement is in its usefulness in ensuring quality of conformance to a specified design. This usefulness is dictated by the extent to which the conversion of greasy wool into product itself modifies the physical characteristics of the wool, and to the extent to which these modifications can be predicted from the greasy wool measurements.

We know that during the primary processing steps (scouring, carding and combing) fibres are lost or removed, fibres are broken and fibres can be discoloured. Hence any measurements made on greasy wool will not be replicated when repeated on the tops produced from this greasy wool. Systematic differences are to be expected and do occur.

Fortunately, the most important characteristic of greasy wool, mean fibre diameter, is usually only marginally changed during processing, with the average value in the top increasing by 0.2-0.4 microns. Hence greasy wool measurements can, in most instances, be used to predict this with a high degree of precision.

Top yield on the other hand is more dependent on the mill. Predicting top yield from the greasy wool characteristics such as yield and vegetable matter base requires adjustment for mill effects. Some generalised adjustments are included in the Schlumberger dry top & noil yield calculation but allowances still need to be made for individual mill effects.

Likewise, prediction of fibre length distribution characteristics such as Hauteur and Coefficient of Variation of Hauteur is not simple, due to the fibre breakage that always occurs during processing.

For these parameters the processing outcome is very highly mill dependent. However, the TEAM trials developed general formulae, based on staple length, staple strength, vegetable matter base, mean fibre diameter, position of break, coefficient of variation of diameter and coefficient of variation of staple length that can be used to predict hauteur, coefficient of variation of hauteur and romaine. Nevertheless, for this to be useful, each mill must derive a “mill factor” to add to the formulae. The “mill factor” is specific to every mill, and corrects the TEAM formulae predictions so that they more accurately reflect the performance of the mill.