The specification discloses a borate microemulsion product. In one embodiment, the borate microemulsion includes from about 24 to about 32 weight percent emulsified sodium pentaborate and from about 24 to about 32 weight percent particulate boric acid suspended therein. The microemulsion has a density of about 9.5 to about 10.5 pounds per gallon at about room temperature. In certain embodiments, the microemulsion has a viscosity of about 1200 to about 1520 at a temperature of from about 66° F. to about 70° F. In certain other embodiments, microemulsion has a viscosity of about 1000 to about 3000 at a temperature of from about 70° F. to about 75° F.