U of S | Mailing List Archive | alt-photo-process-l | RE: Overexposeure was Re:Pinhole gums

RE: Overexposeure was Re:Pinhole gums

I am totally puzzled by your observation and tend to agree that the issues at hand are not related. That is the fact that the prints are grossly overexposed is not related to the size. Actually the thing to do is to expose a step tablet now at your standar time. Is there a gradation, are some steps totally white? Same thing as developing a swatch of dried but unexposed paper, except the step tablet gives you so much more info.
While I never had this happen to me in gum I remember making a batch of carbon tissue that spontaneously hardened because of an additive in a watercolor pigment. I really could not understand why my prints were so overexposed. I pratciacally tried to boil them to no good result.
If hardening of the gum is an issue, because you have to much hardener in the gelatin (I do not kn ow how), try to soak the paper and then print the step tablet.
Keep us posted we could learn something here.

> Date: Sun, 30 Nov 2008 20:04:27 -0800
> From: kthayer@pacifier.com
> Subject: Re: Overexposeure was Re:Pinhole gums
> To: alt-photo-process-l@usask.ca
> Hi Diana, glad you made it home. I lived on an island during one of
> my former "lives" (a very happy one it was) and I know how life runs
> by the ferry schedule on an island.
> Okay, I'm still not sure, so you're saying that all the prints that
> you had trouble with on that paper were printed in the same kind of
> weather, unusually cold and dry, or not? (Actually, I'm not sure it
> matters all that much, since you weren't printing outdoors, but in
> your humidified workspace, but just trying to cover all the bases.)
> The other answer is disappointing :--) because I was hoping to rule
> something out, but if sometimes you could get a fully developed image
> by brushing and sometimes you couldn't, then it really makes no
> sense. We're fond of saying that almost anything that can be said
> about gum can be contradicted, but when we say that, all we mean is
> that gum is so versatile and flexible that the results are affected
> by many different variables and the interactions between them, and so
> different people working under different conditions and with
> different equipment/materials will have different observations about
> the particulars of how gum works. But while that's true, that the
> particulars of gum can vary from one practitioner to another, at the
> same time gum does behave lawfully under a particular set of
> conditions/protocol and should perform in a repeatable fashion
> within one printer's practice, everything being held reasonably
> constant.
> If you could always develop an image by either long still-development
> or by brushing, then the logical conclusion would be that the
> problem is gross overexposure (then the next problem would be trying
> to understand the cause of the overexposure). If you could never
> obtain a fully-developed image by either long still-development or
> brushing, then the logical conclusion would be that the problem is
> either stain or (much less likely IME) an overall hardening of the
> gum layer, as Mark suggests. But if it's sometimes one and sometimes
> the other, then it's impossible to draw even tentative conclusions
> without more information. The only possible, though somewhat
> unlikely, explanation I can think of for this inconsistency might be
> that the weather varied during the period of time you were having
> difficulty printing on that paper, and under different weather
> conditions the overexposure was sometimes not as profound as at other
> times, making it possible to brush-develop the image during those times.
> That said, I have to say that in all my years of printing gum, I have
> only twice seen gum so profoundly overexposed that the image could
> not be developed by long development or by brush-development. Once
> was when someone came to the door when I was exposing a print, and I
> left the print to answer the door and then forgot about it in
> attending to the business of the visitor, and the print exposed until
> the light burned out, a couple of hours at least. The other time
> was when I put a print frame on a black tarpaper roof on a hot sunny
> day and exposed in direct sun for five minutes. In both cases, I
> suspect it was more a thermal hardening issue than straight
> overexposure per se: the gum layer was hardened throughout by the
> heat that was generated in the print.
> But those were both very extreme cases, and I'm not inclined to
> believe that overexposure this extreme could be caused by the
> conditions described here.
> However, the explanation you seem to be satisfied with, that the
> gelatin "dried too quickly" makes no sense either.
> It seems the word "drying" has been used in a confusing way in this
> discussion, which has served to conflate two different issues. You
> have two things going on: the gelatin setting up, and the paper/
> gelatin drying. As the gelatin cools it becomes more solid than
> liquid, but that's not the same thing as the gelatin drying on the
> paper, which has to do with moisture content not temperature.
> Generally it doesn't matter how fast the gelatin dries once it's in
> the paper; the faster the better IME, because I don't like waiting
> all day for it. The garage where I hang my sized paper is "solar
> heated" by virtue of the fact it has no insulation and a metal roof,
> and on a sunny day the sized paper is often dry almost as soon as I
> hang it up. The quickness of the drying has no effect on the
> effectiveness of the size. The possible explanation offered, "the
> sizing dried too quickly, so it was as if the paper had no sizing at
> all" doesn't seem to me to be anchored in observable sizing
> reality. And if you mean the gelatin set up too quickly, then it
> makes even less sense, because when the gelatin sets up too quickly,
> you have a problem of too MUCH sizing, rather than not enough sizing.
> That would be the most likely consequence of sizing outdoors on a
> cold dry day, as David and Chris suggested: the gelatin would set up
> so fast that it would spread on thick and viscous and sit on top of
> the paper rather than soaking in as a liquid, like it should. While
> this is a likely result of sizing outside in cold weather, I'm
> skeptical that this is the explanation for what we're dealing with
> here, for two reasons: (1) Diana says she didn't notice the gelatin
> setting up, and I would think you'd have to be awfully unobservant
> not to notice that. Since she scored a perfect score on the color
> discrimination test, I'm not inclined to describe her as
> unobservant. (2) the problems that getting the gelatin too thick
> and viscous would introduce in printing/development are different
> from the problems Diana describes. Yes, it might make the brush drag
> when coating, but the too-thick sizing would prevent any pigment
> staining problems, so staining wouldn't be an issue, and the too-
> thick sizing would be unlikely to be related to overexposure as
> well. What a proper sizing does is sink into the paper and leave
> the tooth open for the gum to cling to. A too-thick sizing, which
> is what you'd get if you brushed the sizing on too cool when it's
> already setting up, will clog up the tooth so the gum doesn't have
> anything to hang onto. So what happens when you're printing gum on a
> too-thick size layer like that, is that the gum won't adhere to the
> support and will flake off or slough off in development. That's
> obviously not what's happening here, so I don't think the gelatin
> cooling and setting up too fast is responsible for the problems Diana
> describes.
> I did offer a kind of off-the-wall hypothesis about the gelatin
> evaporating off the paper in the cold dry wind. I have no idea if
> that's even possible, but if it were, at least it has the advantage
> of offering an explanation for Diana's problems, if it turns out that
> the problem is stain rather than overexposure. But it's a REEALLL
> long shot.
> I'm inclined to think that the whole sizing thing may be a red
> herring, that the printing problems may be unrelated to the fact that
> the paper was sized on a cold dry day, but that's just conjecture on
> my part. Occam's Razor points that way, I think, because the only
> way to connect the sizing to it it is to come up with a new
> unsubstantiated theory, and I find things usually have a more
> accessible, sensible, logical, and evidence-based explanation when
> it comes right down to it.
> I was working on a way of organizing variables to try to make sense
> of this, but had abandoned it while waiting for answers, hoping to
> rule out some variables at the outset. Now I'm tired and have rather
> lost heart for the enterprise; there are altogether too many unknowns
> in this equation.
> Oh, one more thing, Diana: you seemed to be putting some stock in
> the fact that you were getting a faint printed out image after
> exposure. IME, that means nothing. Sometimes you get a faint one,
> sometimes a strong one, sometimes no printed out image at all; in my
> experience there is no connection between the presence or absence of
> a printed out image, or of how detailed it is, and the quality/
> tonality of the image that eventually emerges from development.
> Good night all, hope any of this is useful to anyone,
> Katharine
> On Nov 30, 2008, at 4:29 PM, Diana Bloomfield wrote:
> > Hi Katharine,
> >
> > Finally found the cat, and we just got home. Whew. It's been
> > pouring rain here for 2 days. Anyway, I sized this particular
> > batch of paper (maybe 25 sheets, both Rives and Fabriano) outside
> > in dry colder than normal weather. Then, over the next few days, I
> > tried printing on both kinds of paper-- I had trouble with every
> > one I tried, though I still have some left. I gave up after a
> > while, thinking it might be my darkroom space which is colder than
> > the rest of the house, but the temperature in there was probably
> > about 60 degrees.
> >
> > I would leave the print in water for hours-- picking it up, nothing
> > had changed from the time I took it out of the vacuum frame. I ran
> > water across it-- still nothing. I then brushed it fairly hard,
> > and that helped-- you could see an image, though there was staining
> > in all the light areas. I only tried one coat on these, because I
> > just didn't like the way it looked-- but on several of them, I did
> > get a fully developed image-- only after brushing continuously.
> > So it sounds like overexposure and looked like something that just
> > hadn't been sized at all (to me).
> >
> >
> > On Nov 30, 2008, at 2:44 PM, Katharine Thayer wrote:
> >
> >
> >> Diana, I keep thinking you're gone, but if you're still there, two
> >> quick questions:
> >>
> >> (1) I'm confused about the conditions under which you're having
> >> these printing problems. Was it only when the weather was cold
> >> and dry, or is it any time you use the paper that was sized when
> >> it was cold and dry, regardless of present conditions?
> >>
> >> (2) You said that brushing "helped" but that the image essentially
> >> didn't develop; I don't understand that. Are you saying that even
> >> with brushing, the image didn't fully develop, or that brushing
> >> after a long soaking that didn't develop an image would eventually
> >> result in a fully developed image?
> >>
> >>
> >>
> >> On Nov 30, 2008, at 11:23 AM, Diana Bloomfield wrote:
> >>
> >>
> >>> Hey Mark,
> >>>
> >>> That's a thought. As advised by the woman at Photographers
> >>> Formulary, I keep the bottled glut in the refrigerator, so when I
> >>> get ready to use it, I take it out and have never even bothered
> >>> to warm it up-- I just add the required amount in the warmed up
> >>> gelatin. But I guess that could have happened. I did have the
> >>> gelatin in one of those electric glue pots that keep everything
> >>> at a constant 140 degrees, so it stayed warm-- until I was
> >>> coating, but I was very quick about it-- I think maybe it just
> >>> dried too quickly. I also used different types of paper when
> >>> sizing, both Fabriano and Rives BFK, and got the same results
> >>> from both. The only difference in what I normally do was the
> >>> (relative) excessive dry cold.
> >>>
> >>> On Nov 30, 2008, at 2:16 PM, ender100 wrote:
> >>>
> >>>
> >>>> Could it be that the hardening agent you are using for the
> >>>> gelatin did not activate in the cold well and then when you
> >>>> coated with the gum, it was causing a hardening of the gum?
> >>>>
> >>>> I would try sizing a sheet in "normal" temperature and humidity
> >>>> and then try a gum print on it and see what happens.
> >>>>
> >>>> Fall seems to be when lots of people have problems with printing
> >>>> due to changes in temperature and humidity.
> >>>>
> >>>> Best Wishes,
> >>>>
> >>>> Mark Nelson
> >>>> Precision Digital Negatives
> >>>> PDN Print Forum @ Yahoo! Groups
> >>>> Mark Nelson Photography
> >>>>
> >>>>
> >>>>
> >>>> On Nov 30, 2008, at 1:11:45 PM, "Diana Bloomfield"
> >>>> <dhbloomfield@bellsouth.net> wrote:
> >>>> From:"Diana Bloomfield" <dhbloomfield@bellsouth.net>
> >>>> Subject:Re: Overexposeure was Re:Pinhole gums
> >>>> Date:November 30, 2008 1:11:45 PM CST
> >>>> To:alt-photo-process-l@usask.ca
> >>>> Hey Katharine, David- Still here-- we were on our way out the
> >>>> door to catch a ferry to get back home, and then our cat managed
> >>>> to hide herself so we couldn't leave. We finally found her
> >>>> hiding in a closet-- anyway-- as far as overexposure-- that is
> >>>> what it sounds like, though I was using the same exposure times
> >>>> as before. So-- since this was without the usual humidity, it
> >>>> couldn't have been overexposure, right? On Nov 30, 2008, at 2:05
> >>>> PM, Katharine Thayer wrote: > > On Nov 30, 2008, at 10:51 AM,
> >>>> davidhatton@totalise.co.uk wrote: > >> That's right Katherine.
> >>>> Higher humidity faster printing..What was >> I thinking?? >> >>
> >>>> It just looks that there is some kind of over-exposure thing
> >>>> going >> on here.., hmmm > > Yeah, I know, it's confusing, and I
> >>>> agree that it looks like > overexposure, that or possibly (but
> >>>> less likely IMO) pigment > stain. I'm trying to work up a flow
> >>>> chart kind of thing that > would help us organize what variables
> >>>> and elements we're looking > at, because reading back through
> >>>> the thread I found the discussion > very confusing. Stay
> >>>> tuned... > kt
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>>
> >>>>
> >>>>
> >>>
> >>>
> >>
> >>
> >
> >

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