Sepia toning

[cliveh]

Is there any other chemical photographic process that give an image more permanence than sepia toning?

 

[fgorga]

I'm no expert but as I understand it, selenium toned silver gelatin prints are at least, if not more, stable than sepia toned prints.

Additionally, platinum/palladium prints are about as stable as prints get.

 

[Nicholas Lindan]

Possibly "Gold Protective Toner." It is rather pricey, though.

The most archival processes may be cyanotypes and platinum and palladium prints.

 

[MattKing]

To be fully protective, selenium toning has to be done to completion, which means a significant change in tone for most papers.
Encaustic work may be the most archival, but that is due to encasing the image in protective wax.

 

[thornhill]

Tim Rudman mentions polysulphide toners like Kodak Brown Toner as being archival. I've never tried it though it doesn't look difficult to home-brew. The finished prints that I've seen images of look attractive. It's recommended toning be done with heaps of ventilation due to the strong odor, and potential for fogging photographic materials. Similar commercially available(?) toners would include Viradon New and Poly-Toner.

 

[scaringi]

This came from a presentation at the Conservation in Archives Symposium. It is now dated (July ‘98) and it is focused on microfilm but I’ve found it helpful.

https://cool.culturalheritage.org/byorg/abbey/an/an12/an12-5/an12-507.html

They found that a sulphide toner like Kodak Brown Toner “. . . gives complete protection in our severe hydrogen peroxide test (2000 ppm), even when used in quite dilute solution (for example, 1 part toner to 200 parts water)."

Their paper raises significant doubt as to the effectiveness of selenium (echoing what @MattKing has already said), “The peroxide tests at IPI [Image Permanence Institute] showed that Kodak Rapid Selenium Toner failed to provide protection against redox blemishes, when used as suggested. If highly concentrated solutions were used, the level of protection increased, but was not complete.”

This paper, along with Rudman’s book, led me to move from selenium to using a thiourea sepia toner (p. 181 in Rudman’s book). I really appreciate its versatility (even though it is stinky) and it is quite nice when used in combination with selenium.

 

[JPD]

I have also read that prints toned in sulphide toners are protected both against oxidation and from sulphur compounds in the enviroment (that is pretty obvious since the prints have already been "yellowed" to the max by the toner). Never store untoned prints with brown/sepia toned ones.

The tests have been done in extreme enviroments, so if selenium toned prints didn't fare as well in them as the sulphide toned prints it doesn't mean that selenium toning is worthless. In a normal enviroment the selenium toned prints may be fine for many generations.

 

[grain elevator]

Never store untoned prints with brown/sepia toned ones.

I've been doing that. What's going t happen to them? (They should be sufficiently washed, I've been testing.)

 

[JPD]

I've been doing that. What's going t happen to them? (They should be sufficiently washed, I've been testing.)

The slow outgassing of sulphur compounds (or ions?) from the sulphide toned prints can cause yellow spots on untoned prints, so it's best to keep them separate. It can take many years before anything happens, but silver is sensitive to anything sulphur.

 

[mohmad khatab]

Agfa Scala with Thiourea.

 

[grain elevator]

The slow outgassing of sulphur compounds (or ions?) from the sulphide toned prints can cause yellow spots on untoned prints, so it's best to keep them separate. It can take many years before anything happens, but silver is sensitive to anything sulphur.

Should there be any outgassing? I thought the silver sulphides are extremely stable?

 

[JPD]

Should there be any outgassing? I thought the silver sulphides are extremely stable?

The sulphide toned prints are very stable indeed, but the silver in the untoned prints isn't and can combine with sulphur ions from the enviroment.

I remember toning prints in Viradon and rinsing them for over an hour with a good flow of water and agitating them by hand, and they still gave off a little sulphur (Hydrogen sulphide) smell for years. Other toners may smell less or not at all, but I still wouldn't trust the prints not to give off sulphur ions.

Also, sulphide toning shouldn't be done in the same room you store unexposed photo papers and untoned prints because it can cause fogging and yellowing. This might also not be seen right away, but you can see it like premature aging of the papers. I had this happen to my Emaks K888 and K883 papers and they were Chlorobromide papers that reacted more easily to toners, so I guess the were more sensitive to the Hydrogen sulphide gas.

Your untoned prints may look fine now stored together with the sulphide toned prints, but they may "age prematurely" and yellow with time. It's better to be safe than sorry.