R19 6" 2X4 KRAFT BATT 144/SF Johns Manville Formaldehyde-free� Kraft-faced thermal and acoustical insulation offers R-Values up to R-49, and is offered in precut batts to fit standard wall cavities or rolls for custom installation in any size cavity. Kraft-faced insulation is ideal for moisture control in exterior walls, reduces sound transmission through walls, ceilings and floors, and can be used in a variety of wood-framed, engineered wood and steel frame construction applications, including new construction and retrofit.