Early work by Ralph G. Nuzzo and David L. Allara on spontaneously organized molecular assemblies informed Whitesides' work on soft lithography. Whitesides and his research group have made significant contributions by developing techniques for soft lithography and microcontact printing. Both microscale and nanoscale techniques are based on printing, molding and embossing, and can be used for the fabrication of patterns and features on many different materials. Soft lithography uses a patterned elastomer as a stamp, mold, or mask to create micropatterns and microstructures. Such techniques have now become standard in the field.