An ultra-low surface finishing process for 6061 T6 type aluminum has been developed by Corning Incorporated, Specialty Materials Division, and has been successfully applied to mirrors up to 13 inches in diameter. This paper presents finish and figure data achieved from the mirror finishing process. Mirror stability is demonstrated through Pre and post thermal cycle surface figure measurements; temperature range of cycle -55°C to +70°C. As an added benefit, the process enables the use of deterministic finishing and enhances the reflective optics resistance to corrosion. Survivability of the reflective optic is evaluated through extended humidity testing.