Nelson Gold Paper Toner (Kodak T-21, GAF 223) produces rich tones that vary from just a hint of warmth to rich sepia browns. The depth of the tone depends upon the duration of time the print remains in the toning bath. The toner is useful in portrait photography where it can be used to diminish the impact of cold black tones. Toning can be stoped any time btween 5 and 20 minutes. Final images are permanent and are formed by a combination of silver sulfide and gold. The toner keeps almost indefinitely ansd its capacity is extended by adding small amounts of gold chloride solution. The toner is relatively inexpensive per print. One liter of solution is used to tone about 300 to 400 8x10 prints (with replenishment), depending upon the tones desired. The satisfing results of this toner has made it a popular toner over the years.

CHEMICAL SAFETY
Potassium persulfate is an oxidizer. It can supply oxygen to a combustible material, thus increasing the risk of fire. Clean up any spilled solid oxidizer with lots of water. Never dispose of excess solid oxidizer in a wastepaper basket. Wash it down the drain with lots of water. Silver nitrate is both an oxidizer and a caustic. In addition to being a potential fire hazard, it can cause skin burns. As with any oxidizer, clean up any spilled solid with water. If you wish to dispose of solid silver nitrate, wash it down the drain with water. If solid silver nitrate should come into contact with the skin, a chemical burn may result. Wash the area with cold water followed by soap and water. Treat any wound in the same manner you would treat a heat burn. When spilled on the skin, dilute solutions of silver nitrate will cause the skin to turn brown. The brown color is due to silver metal bound to the protein of the skin and cannot be washed off. While there are chemical methods for removing the brown stains, the best procedure is to just let them wear off. Gold chloride, like silver nitrate, is a caustic and can cause skin burns. In dilute solution, gold chloride will stain the skin purple. The purple stain cannot be chemically removed. The only procedure for removal of the spots is to let them wear off. If you are concerned with finger stains, we strongly urge you to use rubber gloves, such as Playtex gloves, when working with this toner.

MIXING THE SOLUTIONS

STOCK SOLUTION A

To prepare Stock Solution A, two solutions (called Solution 1 and Solution 2) will be prepared first then mixed. You will need two temporary containers. One container should have a capacity of 1 liter and the other temporary container should be able to hold 16 ml. You will also need a storage container.

SOLUTION 1

Chemical	Amount	Units
Water (125°F/52°C)	750	ml
Sodium Thiosulfate (anhy*)	30	g
Potassium Persulfate	30	g
Cold Water to make	1000	ml

*Sodium thiosulfate, pentahydrate, can be substituted for the anhydrous form. Use 240 g, place the warm water in a temporary mixing container, add the thiosulfate, stir until it dissolves. Add the persulfate and stir vigorously. The solution should turn milky white. If it does not turn milky white, then the water was not warm enough. In such a case, warm the solution until its temperature is greater than 125°F/52°C. Pecipitation of the milky white material is normal.

SOLUTION 2

Chemical	Amount	Units
Water (68°F/20°C)	16	ml
Silver Nitrate	1.3	g
Sodium Chloride	1.3	g

Solution 2 is mixed in a container that is different from that of Solution 1; the two solutions will be mixed in a subsequent step. Place the water in the container and add the silver nitrate. Stir until all of the solid dissolves. All of the silver nitrate must dissolve before the sodium chloride is added; otherwise, solid silver nitrate will be trapped in the solid that forms. Add the sodium chloride. A white precipitate will form. Stir vigorously.

Combining Solution 1 and 2. Both solutions must be at room temperature (68°F/20°C) before they are combined to make Stock Solution A. Stir Solution 2 vigorously to disperse the solid throughout the solution, then pour all of Solution 2 into Solution 1. Stir the combined solution to ensure thorough mixing. A precipitate may or may not be present in the final solution. Transfer the combined solution along with any precipitate (if present), to the storage container.

STOCK SOLUTION B

Stock Solution B is a gold chloride solution and should be prepared in its storage container.

Chemical	Amount	Units
Water (68°F/20°C)	52.5	ml
Gold Chloride	0.25	g

Gold chloride is deliquescent and rapidly absorbs atmospheric moisture. The solid may have liquefied by the time you receive it. Since you will be transferring it to a water solution, prior liquefaction is not detrimental. However, when gold chloride liquefies, some of the liquid clings to the cap of its container. Because of the small amount of gold chloride used in this kit, it is imperative that all of the residual gold chloride in the vial be transferred when you prepare Stock Solution B. Measure the correct volume of water needed in a graduated cylinder. Place a plastic funnel on the Solution B container. Using an eye dropper, add some water to the gold chloride vial, then wash the contents of the vial into the container with additional water. Wash both the vial itself, the cap threads on the vial, and finally the cap. When gold chloride is present in the wash water, it will be yellow. When you are convinced that all the gold chloride has been transferred, pour the water remaining in the graduated cylinder into the Solution B container. Cap and shake (or stir) the container to ensure the solution is homogeneous.

Mixing the Working Solution
To prepare the working solution, one-half of Stock Solution B is added to Stock Solution A. The remaining one-half of Stock Solution B is used as a replenisher for the working solution. Add 26 ml of Stock Solution B to 1000 ml to Stock Solution A: Measure the correct volume of Stock Solution B and in a graduated cylinder and poor it into Stock Solution A. Be sure the container of Stock Solution A will hold the combined volumes. Cap and shake (or stir) the resulting mixture to ensure it is homogenous. Set the working solution aside until a precipitate has formed and settled. An overnight standing should be sufficient. Do not use the working solution until the sediment has formed.

USAGE
Before toning, a wet, freshly-fixed print should be washed a few minutes. Dry prints should be soaked in water. For best results, use two prints; one to be toned and one for comparison. Very carefully decant the working solution into the tray. Do not pour the sediment in the working solution into the toning tray. For proper toning, the working solution must be maintained at a temperature between 100°F/38°C and 110°F/43°C. If you do not have a special warming try, use the two-tray procedure for warming. Place hot water in a large tray and float the toning tray on the hot water. Add additional hot water to the large tray as necessary. Place the print to be toned in the solution and tone to the desired hue. When the desired tone has been reached (5 to 20 minutes), rinse the print in water; fix the print for 5 minutes; and finally wash the print for at least one hour. When the toning session is complete, return the working solution to its storage container.

REPLENISHMENT
Exact measurements cannot be given. In general, about 4 ml of Solution B should be added to the working solution after fifty 8x10 prints have been toned. For example, when toning to a warm brown, add 4 ml of gold solution after each fifty 8x10-inch prints or their equivalent have been toned.

GOLD ON SEPIA
Tone in ordinary sepia. Wash well, then immerse the print in any of the gold toners. The resulting color ranges from reddish-brown to bright orange, depending on the depth of the sepia tone and the length of immersion in the gold bath. Prints intended for this treatment should be dark and contrasty. Refixing and re-washing is recommended.

REFERENCE
Nelson Gold Print Toner, Kit No. 06-0120, Photographers' Formulary (800-922-5255).
Photo Lab Index, Section 15, Supplement No. 172, p. 60.
The Darkroom Cookbook, Stephen G. Anchell, p.158.

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