Dassonville T-55 Direct Selenium Toner produces rich purple to brown tones.

CHEMICAL SAFETY

Selenium is highly poisonous in both powder and vapor forms. Mix and use in a well ventilated room with an appropriate fume mask and gloves.

MIXING THE SOLUTIONS

CAUTION: Never use metal utensils or containers in the preparation of or in the use of toning solutions.

STOCK SOLUTION

Chemical	Amount	Units
Water (125°F/52°C)	100	ml
Sodium Sulfite	25	g
Selenium powder	1	g
Ammonium Chloride	31	g
Cold water	67	ml

Dissolve the Sodium Sulfite in 100 ml of warm water. Add the Selenium powder and slowly heat until the powder is dissolved. Allow this solution to cool to room temperture. Add the Ammonium Chloride to the solution, stirring thoughly until dissolved. Add 67 ml of water, stir to mix.

USAGE
Dilute the stock solution between 1:5 and 1:9. Agitate the print for 2 to 3 minutes with continuous agitation. Wash the toned print thoughly. The working solution deteriorates rapidly, discard after use.

VARIATIONS A small amount of Thiourea may be added to the working solution to vary the tone. The toner may also be used after the print has been lightly tuned with a thiourea based toner.

REFERENCE
Print Toners, Dassonville T-55 Direct Selenium Toner
The Photographer's Master Printing Course, Tim Rudman, p.151.
The Photographer's Toning Book, Tim Rudman, p.183.
The Darkroom Cookbook (2nd Edition), Stephen G. Anchell, p.232.