FORMULARY FX-1 HIGH ACUTANCE FILM DEVELOPER is a metol based film developer, which contains a small amount of potassium iodide. Developer FX-1 produces high-resolution, fine grain negatives, which are suitable for a high degree of enlargement. Normal contrast can be obtained using regular films. Contrast can be easily controlled by adjusting the development time. This developer is probably the sharpest developer ever formulated for films from ASA 25 to 200. Chemicals in this kit are used to make two stock solutions that when diluted will yield 10 liters of working solution with a shelf life of about six months.