[pure-silver] Re: When is Sulphide toner not sulphide toner?
- From: Christopher Woodhouse <chris.woodhouse@xxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sat, 27 Nov 2004 09:25:48 +0000
Apologies, I missed this post and asked the question that you answered here
already.
On 26/11/04 5:55 pm, "Richard Knoppow" <dickburk@xxxxxxxxxxxxx> wrote:
>
> ----- Original Message -----
> From: "Christopher Woodhouse" <chris.woodhouse@xxxxxxxxxxxx>
> To: <pure-silver@xxxxxxxxxxxxx>
> Sent: Friday, November 26, 2004 9:40 AM
> Subject: [pure-silver] When is Sulphide toner not sulphide
> toner?
>
>
>> Whilst it is well understood that sulphide toners protect
>> images from
>> deterioration, when it comes to the odourless sepia
>> toners, like
>> thiocarbimide, I'm assuming that the end product is also
>> silver sulphide.
>>
>> If it is silver sulphide, which we all know has brown
>> tone, why then, if I
>> tone a fixed and washed print in thiocarbimide, before it
>> is bleached, does
>> it have a marked effect upon subsequent bleaching and yet
>> has NO visual
>> effect on the image?
>>
>>
>> --
>> Regards Chris Woodhouse
>>
>>
> I am not sure why this is but the same thing happens when
> using sodium sulfide. If the print is soaked in the sulfide
> bath and rinsed before bleaching it affects the final color.
> The color of the toned image is not due to its being
> sulfide but rather to the effect the sulfiding has on the
> shape and size of the silver particles, which in turn is
> affected by the orginal crystal morphology. As an example
> polysulfide toners tend to shift microfilm toward blue
> rather than yellow. AFAIK this has no effect on the
> protective properties of the toning, but there is no
> research data to show this. The problem with all odd toning
> processes is that one must assume certain things about it.
> Certain toners have been tested in accelerated aging tests
> so their effects are known with some degree of certainty,
> for others its partially guesswork.
>
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@xxxxxxxxxxxxx
>
> ==============================================================================
> ===============================
> To unsubscribe from this list, go to www.freelists.org and logon to your
> account (the same e-mail address and password you set-up when you subscribed,)
> and unsubscribe from there.
>
--
Regards Chris Woodhouse
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you subscribed,)
and unsubscribe from there.
Other related posts:
