This Standard defines correcte invoice weight and specifies a method for its determination for all textile materials except greasy wool. In its application to other natural fibres int he raw state additional procedures may also be required for determining the seight of some extraneous materials. Appendix C lists recommended commercial allowances for the various textile materials. Where these values are not acceptable, the value of the commercial allowance should be the subject of agreement between the parties concerned. This Standard recognizes the convention that an adjustment to the invoice wight shall only be made when the corrected weight differs from the stated invoice weight by more than plus or minus 1 per cent.