The 4 x 4" #32 Magenta Wratten 2 Optical Gel Filter from Kodak is a bright magenta filter that removes green when shooting under fluorescents. It is particularly useful for architectural photography.
Wratten 2 Improvements
More rigid/durable
Easier to handle
Color consistent today, and 6 months from now as well
Wratten 2 Optical Filters are less sensitive to humidity, less prone to static cling
Most Kodak gelatin filters are available in 3 x 3" (75 x 75mm), 4 x 4" (100 x 100mm), 6 x 6" (150 x 150mm), and 14 x 18" (350 x 450mm).