ILFORD ILFOSTOP is a low odour, citric acid stop bath which stops further development of paper or film. It also prolongs the life of the fixer bath, maintaining the activity of your fixer solution, by neutralising the developer.
ILFORD recommend that all black & white films and darkroom papers are rinsed in ILFOSTOP after development, especially when dish/tray processing paper or deep tank processing film.
ILFOSTOP is available in 500ml bottles of concentrate, which makes 10 litres of working strength solution