[Alt-photo] Re: DAS

[Loris Medici]

Uhm, bad news:
- Greg's figure is about the half of what I plan to pour,
and worse,
- Charles' figure is 1/6th of it!!!

I can understand the need for thin tissue for color work, but (with
the exception of gum or gumovers) I only print monochrome, and what
draws me to carbon is the relief. I'm quite happy with what I can get
from pop pd and/or gold toned vdb/argyrotype...

Regards,
Loris.


2013/4/18 Charles Berger <fotocmb at gmail.com>:
> UltraStable pigment films were typically 2.5 mill thick.  A 10% gelatin
> solution coated with a  #100 - 120 coating rod  gave a wet coating
> thickness of @ 250 microns which dried down to @2.5 mils.
>
> How "thick' do you make your films?
>
> Charles
>
>
> On Wed, Apr 17, 2013 at 8:05 PM, Greg Mikol <greg.mikol at ieee.org> wrote:
>
>>
>> I've used a little bit of DAS a couple of years ago. I'm not sure thick
>> tissues is the right choice with this sensitizer. It is an azide compound
>> (technically, diazido), which are made up of nitrogen. Upon exposure to UV,
>> the azide groups break down, releasing nitrogen gas. I didn't do extensive
>> testing, but felt like there was a limit to how thick you could pour, at a
>> maximum of perhaps 0.5 ml/in^2 (sorry for the mixed units) for a 10-12%
>> gelatin solution.
>>
>> Kees...what is the wet thickness of your tissues?
>>
>> Now that I've received my DAS from the APUG group buy, I hope to revisit
>> this some more.
>>
>> --Greg
>>
>>
>> Loris Medici wrote:
>>
>>> Wow, great info. Thanks very much! Doesn't sound too difficult; are
>>> those clearing solutions harmless in terms of longevity in some way?
>>>
>>> BTW, what can you say about 6% sensitizer per gram of gelatin? My aim
>>> is to pour a thick but lightly pigmented tissue for high relief...
>>>
>>> Regards,
>>> Loris.
>>>
>>
>>
>>
>> ______________________________**_________________
>> Alt-photo-process-list | lists.altphotolist.org/**mailman/listinfo<http://lists.altphotolist.org/mailman/listinfo>
>>
> _______________________________________________
> Alt-photo-process-list | lists.altphotolist.org/mailman/listinfo