We place single molecules and assemblies into precisely controlled environments on surfaces. The inserted assemblies and the monolayer matrices that contain them can be designed so as to interact directly, to give stability or other properties to functional supramolecular assemblies. New families of highly symmetric molecules are being developed to yield even greater control and are enabling elucidation of the key design parameters of both the molecules and assemblies. These design elements, in turn, enable controlled chemical patterning from the sub-nanometer to the centimeter scales. We simultaneously develop metrology tools for these methods to give unprecedented insight on the structures, function, and properties of these assemblies.