The Americas, Western Europe, and Oceans are emphasized in the purchasing of cartographic materials. California is the primary area of coverage for purchased imagery. The physical sciences, including bathymetry and topography, are the primary subject areas. Land use, natural resources, and urban studies form a secondary level of collecting parameters. Type of publishers .
Government agencies publish and distribute the majority of the collected materials.
GeoCenter in Germany is the most used private vendor, with the rest of the materials coming from approximately 4,000 different vendors and producers throughout the world. Topographic and bathymetric series constitute a large portion of collected cartographic materials. The quantity of individual sheet maps collected is not nearly as large. Hard-copy images are preferred in negative or positive transparency roll format. Color prints usually form a secondary level.