[Alt-photo] humidity

Ralph Rinke ralphrinke at telus.net
Fri May 26 17:33:05 UTC 2017


Hello Bob,

This may be of interest, have a look at Stan Klimek’s “notes on platinum printing.pdf”.

It is also Appendix G - Elements of Platinum Printing, page 211 in Dick Arentz’s 2nd edition of Platinum & Palladium Printing.

Download the pdf file here:  http://stanklimekstudio.com/journal.html <http://stanklimekstudio.com/journal.html> 


He has a paragraph on humidifying and also mentions to “humidify again at 75% for 8 - 10 minutes” before exposure.



Ralph




> On May 26, 2017, at 9:34 AM, Bob Cornelis via Alt-photo-process-list <alt-photo-process-list at lists.altphotolist.org> wrote:
> 
> Thanks Ned
> 
> I wondered if I had missed an important reference in that 700+ page book!
> That's an interesting statement, I have heard from others recently that
> their experience is different than this. Doesn't look like this reference
> is in regard to his formula, just cyanotype in general.
> 
> In any case, my humidity is certainly staying in what he describes as
> "normal relative humidity" (50 +- 10).
> 
> Bob
> 
> 
> On Fri, May 26, 2017 at 9:19 AM, Ned Lewis via Alt-photo-process-list <
> alt-photo-process-list at lists.altphotolist.org> wrote:
> 
>> In Mike Ware's book "Cyanomicon", he states:
>> 
>> The prevailing relative humidity has very little effect on the results of
>>> printing in cyanotype, but it can profoundly affect some of the other
>>> iron-based processes.
>> 
>> 
>> 
>> 
>> On Fri, May 26, 2017 at 8:30 AM, forums--- via Alt-photo-process-list <
>> alt-photo-process-list at lists.altphotolist.org> wrote:
>> 
>>> In my understanding, humidity should be nearly equivalent between cyan
>> and
>>> pt/pd. (I have a limited understanding of Cyanotype but this was what we
>>> did at MM Workshops.)
>>> 
>>> HPR is especially sensitive to humidity and I recommend no less than 45%
>>> and no more than 66% and also to make sure your temperature is under 74
>>> degrees F. High humidity and high temperature can result in issues with
>>> this paper.
>>> 
>>> Low humidity and result in even more issues though (streaking, etc). This
>>> paper also needs specific amounts of Tween20 or PhotoFlo (surfactants) or
>>> the solution will not go in properly.
>>> 
>>> All in all, the variables must be tested in a scientific way before
>>> optimal conditions are met.
>>> 
>>> best,
>>> Walker
>>> 
>>> 
>>> 
>>> 
>>>> On May 26, 2017, at 11:02 AM, Bob Cornelis via Alt-photo-process-list <
>>> alt-photo-process-list at lists.altphotolist.org> wrote:
>>>> 
>>>> Keith
>>>> 
>>>> I've looked through all the cyanotype docs on Mike Ware's site and
>>> haven't
>>>> found anything addressing my question about specific humidity
>>>> guidelines/recommendations for Ware cyanotype, hopefully I just didn't
>>>> overlook it. Took a more cursory look for pt/pd info but it seems most
>> of
>>>> that on the site pertains to some revisions Mike has made to that
>>> process -
>>>> not sure it would pertain to the classic formula even if there was
>>> specific
>>>> humidity info (which I also didn't see).
>>>> 
>>>> So I'm still open to input from anyone out there who has come to some
>>>> conclusions about this. Is there a range within which you want to try
>> to
>>>> stay? I know some people resort to humidifiers and de-humidifiers to
>>>> maintain certain levels, don't want to do this if I'm in the "safe
>> zone",
>>>> but open to it if I'm not and it matters much.
>>>> 
>>>> With my pt/pd work I was taught to dry the coated paper to somewhat
>> less
>>>> than bone dry (as opposed to cyanotype). I'm thinking that this is
>> meant
>>> to
>>>> address the sensitivity to that process to humidity. But my methodology
>>> for
>>>> that is not very precise.
>>>> 
>>>> One reason I'm interested is that I'm suddenly getting radically
>>> different
>>>> (and strange) results with cyanotype on HPR in terms of how the coating
>>> is
>>>> behaving - only difference in workflow is that the humidity has gone up
>>>> about 10% in my studio since last time I worked (from 50% to 60%).
>> Still
>>>> testing what might be going on there.
>>>> 
>>>> Bob
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> On Thu, May 25, 2017 at 11:44 AM, Keith Schreiber via
>>>> Alt-photo-process-list <alt-photo-process-list at lists.altphotolist.org>
>>>> wrote:
>>>> 
>>>>> Not off the top of my head, but Mike has a lot of information on his
>>>>> website <http://www.mikeware.co.uk/mikeware/main.html>. I'm sure you
>>> can
>>>>> find it there.
>>>>> 
>>>>> Cheers,
>>>>> Keith
>>>>> 
>>>>> Keith Schreiber
>>>>> jkschreiber.com
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>>> On May 25, 2017, at 12:26 PM, Bob Cornelis via
>> Alt-photo-process-list <
>>>>> alt-photo-process-list at lists.altphotolist.org> wrote:
>>>>>> 
>>>>>> Does anyone know what the recommended humidity range is for
>>>>>> 
>>>>>> 1) cyanotype (Ware)
>>>>>> 2) pt/pd
>>>>>> 
>>>>>> I haven't found any specific info like this in any of my alt process
>>>>> books,
>>>>>> just general comments that humidity makes a difference.
>>>>>> 
>>>>>> Thanks!
>>>>>> Bob
>>>>>> 
>>>>>> --
>>>>>> 
>>>>>> http://www.bobcornelis.com
>>>>>> _______________________________________________
>>>>>> Alt-photo-process-list | altphotolist.org
>>>>> 
>>>>> _______________________________________________
>>>>> Alt-photo-process-list | altphotolist.org
>>>>> 
>>>> 
>>>> 
>>>> 
>>>> --
>>>> 
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> 
> 
> 
> -- 
> 
> Color Folio
> www.colorfolio.com
> 
> 2550 Lewis Dr.
> Sebastopol, CA 95472
> 707.824.8910
> 888.212.7060 toll free
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