A-D Strips provide a simple and safe method for detecting, measuring, and recording the severity of "vinegar syndrome" in your acetate photographic film collections. A-D Strips, developed and manufactured by IPI, are dye-coated paper strips designed to detect and measure the severity of acetate photographic film deterioration ("vinegar syndrome") in film collections. Vinegar syndrome is a slow form of chemical deterioration that causes film to shrink, buckle, and emit a strong vinegar odor. These acid-base indicator papers change color in the presence of acidic vapor given off by degrading film, providing an objective method to document the extent of vinegar syndrome and to determine when acetate cinema film, microfilm, and pictorial film should be duplicated. IPI received a Technical Achievement Award from the Academy of Motion Picture Arts and Sciences in 1997 for developing A-D Strips. Each package contains 250 detector strips (1 1/2" x 3/8"), a color-reference pencil, and detailed instructions for use.