Sistan or Fuji Ag-Guard provide image protection but not
as great as toning in a sulfiding toner. Gold toner will
preserve the blue color. Gold toner shifts the image color
toward blue and slightly intensifies it. Gold is very
effective in protecting the image but is expensive.

Kodak GP-1 Gold Protective Solution
Water                                750.0 ml
Gold Chloride (1% stock solution)     10.0 ml
Sodium Thiocyanate                    10.0 grams
Water to make                          1.0 liter

To  make the Gold Chloride solution dissolve 1.0 gram of
Gold Chloride in 100.0 ml of water. Gold Chloride comes in
1.0 gram containers.

Mix the Thiocyanate separately in 125 ml of water. Add it to
the Gold chloride solution slowly with rapid stirring.

The toner does not keep and should be mixed just before use.

For use treat well washed prints in the above solution for
10 minutes at 68F. Then wash for 10 minutes and dry as
usual.

The capacity of the above is about 30 8x10 prints per
gallon.

The long treatment time of GP-1 is probably excessive for RC
paper. But if used with RC the final wash can be much
shorter, no longer than 2 to 4 minutes.

 This toner will cause only a very slight shift to blue on
some papers and none on other papers.

Could you post, or point me to where I can find, the formula for
Kalogen Derivative?  I've never heard of it, but like the idea of
getting blue prints without gold toning

Thanks