Ilford Ilfostop is an acidic stop bath for black and white films and papers. Ilfostop is low odor, which is a pleasant feature when working in the darkroom. The stop bath reduces spotting and helps to maintain the activity and prolong the life of the fixer solution. Using Ilfostop stops the development process immediately. Dilution: 1 + 19 Yield: 15 films, 3 m² RC paper or 1.5 m² FB paper