This part of ISO 787 specifies a general method of test for determining the oil absorption value of a sample of pigment or extender. The oil absorption value is usually required to be compared with the value determined at the same time on an agreed sample of the product. NOTE — When this general method is applicable to a given pigment or extender, only a cross-reference to it should be included in the International Standard relating to that pigment or extender, with a note of any detailed modification which may be needed in view of the special properties of the material in question. Only when this general method is not applicable to a particular material should a special method for determination of oil absorption value be specified.