Abstract: A general field isolation rubber dam with particular applicability in the field of dentistry. An operative insert, in the form of a wire, stamping, or the like, is embedded in or applied to a sheet of elastomeric material such as is used in conventional rubber dams. The operative insert may be elastic, malleable, resilient and deformable or rigid. The operative insert is usually in the form of a closed loop and an opening or openings for defining an operative field is created in the rubber dam material interiorly of the closed loop. The operative insert assists in isolating tensile forces in the rubber dam membrane outside of the insert from distorting the general field isolation dam adjacent the operative field.