There is a photo chemical that I use that makes a very dark black.
It is Rapid Sellinium Toner and made by Kodak.
Sodium selenite the source of the selenium in the Kodak Rapid
Selenium Toner is a very dangerous chemical to work with. It is very
toxic and causes birth defects. I would not have it in my studio and
would suggest if you have it in yours you handle it with extreem
caution using proper safety gear and ventilation.
Here is some of the health data from the MSDS for Sodium Selenite
Acute toxicity of soluble selenium compounds is high. A general
tissue poison like arsenic, presumably attacking sulfhydryl
Irritant to the respiratory system. Soreness, coughing, labored
breathing are symptoms which may subside and return. Lung edema
may occur in acute cases. Cases with flu-like symptoms resembling
metal fume fever within 24 hours of exposure have been reported.
Toxic. May be fatal if swallowed. May cause severe stomach
Causes severe irritation. Symptoms include redness, itching and
May cause severe irritation, redness, pain.
Chronic selenium intoxication may cause depression, nervousness,
dermatitis, gastrointestinal disturbances, giddiness, garlic
odor of the breath and sweat, moderate emotional instability,
excess tooth cavities, loss of fingernails and hair, metallic
taste in the mouth, respiratory tract irritation, fatigue,
allergic eye reactions, and severe skin lesions. Selenium
intoxication has caused blood, liver, kidney and spleen effects
in laboratory animals.
Aggravation of Pre-existing Conditions:
Pepole with a history of asthma, allergies, known sensitization
to selenium, a history of other chronic respiratory disease,
gastrointestinal disturbances, disorders of the liver, blood or
kidneys, or recurrent dermatitis would be expected to be at
increased risk from exposure. Special consideration should be
given to women of childbearing age since the possibility that
selenium may be teratogenic might place these women in a high
In laboratory animals, this compound has caused both birth
defects and damage to the reproductive system.
James Binnion Metal Arts