Formulary's 120 ED High Contrast Paper Developer is a catechol-based paper developer that is similar in composition and results to the Edwal 120 developer. Formulary 120 ED produces neutral to cold tones with very high contrast (1/2 to one grade higher than normal). In addition, rich deep blacks with an abrupt tonal range can be expected. Formulary 120 ED should not be confused with Formulary 120 (a very soft-working developer). The chemicals provided yield a stock solution, which is diluted to make the working solution. The stock solution is stable for 3 to 4 months. The working solution has a high capacity but limited life.