All preservation projects involve meticulous study and planning before actual conservation begins. The Star-Spangled Banner Project began with a careful examination of the flag, accompanied by extensive consultation with Museum curators and outside advisors. Conservation and textile specialists assessed damage to the flag by examining the flag’s fibers and dust vacuumed from the flag's surface. A 1996 conference brought experts together to consult on the treatment plan. In 1999, the Star-Spangled Banner was moved into a state-of-the-art laboratory to undergo extensive conservation treatment. Custom-designed to provide a safe, clean environment for the 30-x-34-foot flag, the lab was also constructed with a glass wall so visitors could watch the conservators working.  Conservators use pH readings to measure the levels of acid or base in the fibers of the flag. The stability of organic materials, such as the fibers of the flag, is dependent on their acid and base levels. Protein, such as wool, is generally stable in a pH range of 4 to 8, while cellulose material, like cotton or linen, is stable in a pH range of 6 to 8. The pH information helps the conservators determine what type of cleaning is necessary on the flag.  Color readings are used by conservators and scientists to study the flag. A spectrophotometer is an instrument that collects color readings and helps analyze dyes. The spectral data allow non-destructive analysis of the dye material and permit an accurate assessment of the true color of the flag. Curators and exhibition designers will use this information to determine the best way to light the flag in its future display.  Conservators arranged for the Star-Spangled Banner to be photographed at key points during the conservation treatment. Because of the flag’s size and the confined lab space, it could not be photographed as a whole. The photographers took seventy-three shots. Using computer technology, each individual frame was pieced together, like a puzzle, into a composite image of the flag.  The conservators examine the flag both microscopically and macroscopically. Fiber analysis of sewing threads and visual observation help determine the chronology of the many stains, mends, and patches found on the flag.  The rod-like formation inside this white wool fiber from the Star-Spangled Banner is typical for wool that is in good condition. The fiber was deliberately broken to reveal its intact interior structure, which contrasts with that of a damaged fiber.  A damaged white wool fiber from the Star-Spangled Banner shows that the rod-like formations that appear in the center of normal fibers have physically broken down. Chemical exposure and actions like bending, crushing, and rubbing degrade the fibers and make them more susceptible to breaking.  Back to top A conservator analyzes the dyes used on the wool of the flag. The data were obtained with a spectrophotometer, which collects the spectra of reflected light. National Museum of American History, Smithsonian Institution Preservation includes preventive measures to extend the life of an object for display and research. Conservation is the physical or chemical treatment of an object to stabilize it. Restoration, a process not normally used by history museums, makes an object appear newer by bringing it closer to its original condition.