D-25 Fine Grain Film Developer is a fine-grain film developer that contains metol and a mild silver solvent, sodium metabisulfite. The grain obtained with D-25 resembles that obtained with Developer 12. However, D-25 contains metol rather than the toxic p-phenylenediamine found in Developer 12. Contrast is normal with D-25, but softness may result.

D-25 is reputed to be a non-staining developer, however, staining and dichronic fog have been reported with modern fine-grain films. Therefore, the developer should be tested with your current film before this developer is used extensively.

CHEMICAL SAFETY
Some individuals become sensitized (develop allergic symptoms or rashes) when using metol. If this should happen, discontinue use and consult a physician. We recommend you wear a dust mask, splash goggles, rubber gloves and a rubber apron anytime you are mixing dry chemicals.

MIXING THE WORKING SOLUTION
You will need a dark brown bottle with a capacity of one liter and a mixing container.

Chemical	Amount	Units
water (125°F/52°C)	750	ml
Metol	7.5	g
Sodium sulfite	100	g
Sodium Metabisulfite	15	g
Cold water to make	1000	ml

Place the warm water in the storage container and add a pinch of sodium sulfite. (The Sodium sulfite minimizes the initial oxidation of the metol. If more sulfite is added at this point, the metol will not dissolve.) Add the metol and stir, making sure all the metol has completely dissolved. Add each chemical in the order given making sure each dissolves completely before adding next. Finally add cold water to bring the final volume in the container up to 1 liter and stir to ensure the solution is thoroughly mixed.

SHELF LIFE
Unused Developer 25 has a shelf-life of about 6 months in a full and tightly capped bottle.

MIXING THE REPLENISHER
You will need a 1 liter brown bottle or other suitable container. We recommend you wear rubber gloves, splash goggles, dust mask and a rubber apron whenever mixing dry chemicals.

Chemical	Amount	Units
water (120°F/48°C)	750	ml
Metol	10	g
Sodium sulfite	100	g
Sodium Metaborate (Kodalk)	20	g
Cold water to make	1000	ml

Place the warm water in the storage container and add a pinch of sodium sulfite. (The sodium sulfite minimizes the initial oxidation of the metol. If more sulfite is added at this point, the metol will not dissolve.) Add the metol and stir, making sure all the metol has completely dissolved. Add each chemical in the order given making sure each dissolves completely before adding next. Finally add cold water to bring the final volume in the container up to 1 liter and stir to ensure the solution is thoroughly mixed.

CAPACITY
The capacity of the developer is 4 rolls (320 square inches) per liter. The capacity can be extended to 25 rolls per liter by replenishment with DK-25R Replenisher (Cat. No. 01-0057). Add replenisher at a rate of 38 ml per liter of developer for each roll of film developed for the first 15 rolls developed then add 23 ml of the replenisher per liter of developer per roll developed.

Discard the developer after 25 rolls have been developed or at the end of one month from its first use, whichever comes first.

USAGE
We recommend a development time of 15 to 20 minutes with agitation each minute. Follow your normal develop, stop, fix, wash, clear and wash procedure. Developer 25 can be used at 25°C/77°F, however the development time should be shortened to about 11 minutes. The negative will still have fine grain and low to medium contrast.

REFERENCE
Film Developer 25, Kit No. 01-0053, Photographers' Formulary (800-922-5255),
Replenisher DK-25R Kit No. 01-0057, Photographers' Formulary (800-922-5255),
Film Developer 25, The Negative, Ansel Adams, p. 253.
Film Developer 25, The Film Developing Cookbook, Stephen G. Anchell and Bill Troop, p. 106
Film Developer 25, The Darkroom Cookbook, Second Edition, Stephen G. Anchell, p.215.

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