The procedures that follow can be used to analyze mixtures of many commonly occurring textile fibres. In selecting these procedures, a number of possible methods were considered. Interlaboratory analyses of prepared fibre mixtures of known composition were carried out, and only those methods found to be satisfactory were accepted. In most cases, the scope of the method is given, and provision is made for estimating the accuracy of the result obtained.

If the types of fibres present in the mixtures are not known, they must be identified before quantitative analysis can be undertaken.

The accuracy of the results obtained with these methods decreases if non-removable non-fibrous materials are present.

The manual separation method is technically equivalent to International Standard ISO 5088, Textiles - Ternary fibre mixtures - Quantitative analysis, Section 3, "Method of analysis by manual separation," but it is written in the same format as the remainder of the methods detailed herein.

The chemical test methods are similar to International Standard ISO 1833, Textiles - Binary fibre mixtures - Quantitative chemical analysis.

For the quantitative analysis of fibre mixtures for which methods have not yet been included in this document, reference may be made to the methods issued by the American Association of Textile Chemists and Colorists (AATCC), the British Standards Institution (BSI), the International Organization for Standardization (ISO) or the ASTM International.