[alt-photo] Re: thiourea/thiourea dioxide

[Daniel Williams]

On 9/10/2011 12:49 PM, Christina Anderson wrote:
> Anyone know the difference between thiourea/thiocarbamide and thiourea dioxide, and are they at all interchangeable in photographic processes/toning?
>
> Christina Z. Anderson
> christinaZanderson.com
>
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>
Christina,
They are different and produce distinctly different results.

Thiourea/thiocarbamide - different names for same thing - is an "odorless" sepia toner.

Thiourea dioxide is different and is also called FSA (formamidine sulphinic acid and is also known as Manotone toning. As if it needed still more names, the supplier I bought it from calls it Thiox.

Tim Rudman has articles on both these toners is his toning book.

Dan Williams
Enumclaw WA