The particle size of organic pigments used in modern coatings is extremely fine. Since these individual pigment crystals are typically less than 1 μm in size, they are difficult, if not impossible, to characterize and identify by microscopical means. The occurrence of occasional pigment aggregates may help identify a pigment to a microscopist who is familiar with a variety of known pigments under controlled conditions. More often, however, such observations provide a qualitative basis for comparison of questioned and known paints without leading to identification of the specific pigments involved. Microscopic observations of this type are assisted by the use of a high-magnification oil immersion objective and condenser with numerical apertures of 1.25 or greater.