[Alt-photo] humidity

Bob Cornelis bob at colorfolio.com
Fri May 26 17:40:23 UTC 2017


Ralph

Thanks for pointing me at this - it looks like there is a lot of good
reading there!

Bob


On Fri, May 26, 2017 at 10:33 AM, Ralph Rinke via Alt-photo-process-list <
alt-photo-process-list at lists.altphotolist.org> wrote:

> 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
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>>
> >>>> Color Folio
> >>>> www.colorfolio.com
> >>>>
> >>>> 2550 Lewis Dr.
> >>>> Sebastopol, CA 95472
> >>>> 707.824.8910
> >>>> 888.212.7060 toll free
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> >>>> Alt-photo-process-list | altphotolist.org
> >>>
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> >>> Alt-photo-process-list | altphotolist.org
> >>>
> >> _______________________________________________
> >> Alt-photo-process-list | altphotolist.org
> >>
> >
> >
> >
> > --
> >
> > Color Folio
> > www.colorfolio.com
> >
> > 2550 Lewis Dr.
> > Sebastopol, CA 95472
> > 707.824.8910
> > 888.212.7060 toll free
> > _______________________________________________
> > Alt-photo-process-list | altphotolist.org
>
> _______________________________________________
> Alt-photo-process-list | altphotolist.org
>



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