This part of ISO 9184 specifies two methods for determining the weight factor of fibres used in the fibre furnish analysis of paper, board and pulp. In this part of ISO 9184, the weight factor is obtained either by a comparison method or by calculating from the fibre coarseness. This part of ISO 9184 is applicable to all kinds of fibres of pulps from unmixed wood species. In this context, it means pulps which do not contain more than 5 % of other fibres with an essentially different weight factor (see ISO 9184-1:1990, annex A).