The Ultrafine MONOBATH Black and White Developer is a ready to use (not a concentrate) liquid developer/stop bath/fixer that develops and fixes all in one shot and is reusable to boot. You can process around 16 rolls with each bottle. Each time you re-use allow around an additional 15 seconds of development time for every re-use. When in doubt, over process a little as this allows the film to "clear" with the repeated use. Developing for 3.5 minutes at 75°F (Fahrenheit) is an optimal starting point. This is a single step process, do not dilute. You can adjust development as you experiment to your own preferences. For example if you go to 68°F, the recommended development time is 5.5 Minutes. This is considered an archival process as long as you properly wash your film for 20 -25 minute post development. You can drastically reduce your wash time by utilizing an Ultrafine Archival Wash type product to your rinse. Due to the abbreviated development times agitation is recommended, around every 8 - 10 seconds. This product like many of our fun offerings lends itself to experimentation and creative utilization. Enjoy! Reusable, all-in-one solution,l NOT a concentrate - Ready to use (or re-use)