Describes procedures that may be used for the qualitative determination and identification of the mineral constituents of filled and coated papers. Due to the similarity in chemical composition and physical size and shape of some of the various possible constituents contained in a given paper specimen, more precise quantitative methods may at times be required for positive identification. It is recommended that one become thoroughly familiar with this method by analyzing paper samples of known mineral component content.
ANSI/TAPPI T421 om-2012 history
2012ANSI/TAPPI T421 om-2012 Qualitative (including optical microscopic) analysis of mineral filler and mineral coating of paper