Thin sections can be described quantitatively by point counting as well as qualitatively in terms of dominant rock fabric, microfacies, mineralogy, pore types, biotic components or diagenetic overprints. Grain size and sorting can be measured from thin sections either exactly by point counting or approximately by comparator method. An interpretation of the paragenetic sequence can be supplied, as well as photomicrographs and comprehensive petrographic descriptions. Whenever possible, a rapid petrographic screening of existing thin sections should be done as preparation for core description, so that important sedimentologic and diagenetic features can be properly recognised and recorded during core logging.