Fiber analysis of paper and paperboard, Test Method TAPPI/ANSI T 401 om-20 

This method provides a procedure for the identification of the kinds of fibers present in a sample of paper or paperboard and their quantitative estimation. This method requires the analyst be skillful and experienced in the field of pulp and paper microscopy.

The analyst must make frequent use of standard samples of known fiber composition or of authentic fiber samples and must become thoroughly familiar with the appearance of the different fibers and their behavior when treated with the various stains.

Morphological characteristics help identify special fibers such as straw, flax, esparto, soft woods, such as southern pine, Douglas fir, western hemlock, and various species of hardwoods, so that the correct weight factors may be applied. A knowledge of morphological characteristics of the different fibers is essential for their identification. More information on this subject is given in the Appendices.

It is reported that fiber analysis in highly refined or secondary fiber sheets is very difficult to perform.