[alt-photo] Re: IDEA? NEW ALT PHOTO BOOK

Fri Apr 23 17:48:37 GMT 2010

Chris ponders "My question is does each layer you do of dichromated gum on
top of a layer of previously hardened gelatin also affect the gelatin below
(another colloid) and does it, in fact, affect a layer of PVA in the same
way?"

I've been wondering the same thing, and I have to thank Chris for doing the
heavy thinking here regarding the possible differences between the
interactions of gum/pva and gum/gelatin.  As Paul mentions, I noticed the
same things you did about how comfortably hardened (or so I thought) layers
can suddenly go all "fragile" again.  Very frustrating.  I noticed some
degree of staining, but that seemed to go away with higher PVA/water ratio.
I'm using 1 to 1.5, PVA to water.

I SO WANT this PVA to work, because like you say, it is a magic bullet.  I
never realized how much I hated the gelatin/glut/hotplate ritual, until I
started using PVA.  But, just as soon as I get these 35 pictures done for a
show, I'm going back to gelatin!  That is, until I get another offer for a
35 picture show!  The PVA just makes everything go so FAST.  But I just hate
the shiny surface.  Some of my "fans" have noticed the difference in the
surface and are bemoaning the change.  I'm getting request for things done
the "old way" from people that I never would have thought would notice these
things.

Personally, and I don't have any empirical data to back this up, but a
gelatin sized print gives the appearance of being "blended", while the PVA
prints just look like a stack of layers.

Keith

On Fri, Apr 23, 2010 at 8:31 AM, Christina Anderson <zphoto at montana.net>wrote:

> Bob,
>
> I think it could be a good thick chapter of a book...
>
> I am probably opening up a can of worms here...
>
> I've been using the Gamblin PVA size now and taught it to my class this
> semester in place of glutaraldehyde hardened 2.8% gelatin (6ml of 2.5% per
> liter), and it is a great teaching method and really user friendly.  Boy was
> my life easier--no hot plate, massive sizing day, mess, toxicity.  PVA you
> can just "size as you go". It is the "magic bullet" of teaching for sure.
>
> I use it 1+2 on Artistico.   I found more issues with staining with PVA
> than with glut/gelatin but that I think is specifically related to having to
> determine the dilution of PVA for each specific paper.  I almost think
> Fabriano might benefit from either a 1 + 1.5 or an intermediate layer of
> sizing between multiple coats. But at a point, then, PVA becomes too slick
> and plasticy.
>
> However, after having worked with it all semester I slightly prefer
> glut/gelatin.  **But** I am not sure I prefer the latter enough to go to all
> the trouble to do it.  With tray sized sheets gelatin is no big deal, but
> with 15x22 size sheets it is a pain. PVA wins, hands down, for
> user-friendliness.
>
> I will be finishing up two large gum projects this summer so we'll see by
> the end of summer how I feel--if I go back to gelatin in my own work, in
> other words.  I will continue to teach the non-toxic PVA method, but parts
> of me think I should still at least show students traditional sizing because
> of a concern I am feeling.
>
> My concern is this:  when I take a print out of the water to hang to dry,
> even the border of the print is what I would call "unstable"--meaning a
> fingerprint on it will mar it quite extensively in a way I have not seen
> with gelatin sized paper. Anecdotally, a rewetted PVA print SEEMS also less
> stable--layers still manipulatable.  Is that an issue?  I don't know.  My
> question is does each layer you do of dichromated gum on top of a layer of
> previously hardened gelatin also affect the gelatin below (another colloid)
> and does it, in fact, affect a layer of PVA in the same way?  Or can the
> layer of gelatin even GET rehardened repeatedly with each succeeding layer
> of dichromated gum or is it hardened once and for all with the glut and that
> is it--successive layers do nothing?
>
> Or is this just a "hydrophilic" thing, or that gum is (how would you say)
>  "attracted" to PVA in the same way it is to a surface of gelatin?  Are, in
> effect, PVA and gelatin truly interchangeable in sizing or is it possible
> that each layer of hardened gum has better adhesion to a layer of gelatin
> vs. a layer of PVA, probably only visible at the microscopic level?
>
> Maybe the scientists of the list can answer these questions and put my mind
> to rest, because my lurking fear is that the gum print on top of the PVA may
> not be as stable in the long run as one on top of gelatin.  A non-scientific
> test I will do in a couple months is soak a PVA'ed print and a gelatin-sized
> print, old ones, side by side, and scratch and see the results. But I don't
> know if that proves anything.
>
> I hope someone will come on list and say this fear is completely unfounded,
> that both sizings create equally stable final prints. Anecdotally, a
> rewetted PVA print SEEMS also less stable--layers still manipulatable.  Is
> that an issue?  I don't know.  My question is does each layer you do of
> dichromated gum on top of a layer of previously hardened gelatin also affect
> the gelatin below (another colloid) and does it, in fact, affect a layer of
> PVA in the same way?  Or can the layer of gelatin even GET rehardened
> repeatedly with each succeeding layer of dichromated gum or is it hardened
> once and for all with the glut and that is it--successive layers do nothing?
>
> I have no answers, just asking the hard questions....on this quest for the
> most perfect, easiest size.
>
> Now, as far as other processes aside from gum....salt...hmmm....
>
> Chris
>
>
> Christina Z. Anderson
> christinaZanderson.com
>
> On Apr 22, 2010, at 8:54 PM, BOB KISS wrote:
>
> > DEAR LIST,
> >
> >            I have been faithfully reading most postings on this list
> since,
> > I think, 1998.  Many, many postings have been very informative about the
> > amazing number of options for sizing many different kinds of paper for
> the
> > many alt processes.  I really think it is time for someone to collate all
> > this info into a new alt photo book.  I hereby propose that the title be,
> > SIZE MATTERS.  Any takers (as it were)?  ;-))
> >
> >                        CHEERS!
> >
> >                                    BOB
>
> > Please check my website:  <http://www.bobkiss.com/>
> http://www.bobkiss.com/
> >
> > "Live as if you are going to die tomorrow.  Learn as if you are going to
> > live forever".  Mahatma Gandhi
> > ______________________________________________
> > Alt-photo-process-list | http://altphotolist.org/listinfo
>
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