Re: platinum chemistry

From: Jeffrey D. Mathias ^lt;>
Date: 03/10/04-10:24:52 AM Z
Message-id: <>

Jim Collum wrote:
> I was reading in one of the online FAQ's that after mixing the platinum
> with the Ferric oxalate, you should let it sit for an hour before
> coating. I'm currently working with Ziatypes.. is this necessary for
> this process as well? Since I haven't been doing this, what gains should
> I see?

What you may notice is a degradation of image quality. This might
likely be a loss of substance, loss of maximum density (different from
the previous) or graininess, and more pronounced when using more
contrast agent. I have never noted any improvement, unless maybe if I
considered the degradation an improvement. Waiting an hour or more
before coating as well as after coating and before exposure will likely
lead to problems. It is recommended to keep stock solutions pure and
separate as metal solution, sensitizer solution and contrast solution.

If your stock solutions are properly ready (note that some strong
solutions may need warming), they should readily mix and be ready to
coat with a quick stir. Making some the stock solutions may require
some time, even a day, to go into solution.

Jeffrey D. Mathias
Received on Wed Mar 10 10:25:28 2004

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