Most toners are somewhat toxic. T-8 is no more so that other
"sepia" toners but does emit some hydrogen sulfide gas so has
that "rotten egg" odor and should be used with good ventilation.
One advantage of polysulfide toner is that it affords
protection without full toning. I don't know the minimum amount
but it should provide protection before causing a noticeable
color change.
T-8 is slow but since one is only partially toning that may
be an advantage.
Kodak published a couple of combination toner formulas which
have posted to this list in the past. These are a mixture of
Kodak Brown Toner (T-8) and KRST. I think it was sold as
Polytoner. I found it acts very quickly, perhaps due to the
carbonate in it. One must use a stop bath of sulfite. Wash aid
works for this. That also removes any orange or brown stain left
by the toner.
As far as gloves, I agree they are a bother but I would avoid
getting my hands in most photographic solutions. In any case use
tongs.
I don't know the shelf life, probably very long.
Note that any sulfide toner will provide protection but
other than T-8 the toning should be carried out to completion.
Same for Selenium toner and Gold toner. Partial toning does not
work.
I have heard reports that Agfa Sistan does work but have
still not seen any research on it. Sistan does not affect the
color or structure of image, which makes it useful for microfilm.
On 8/8/2021 9:58 AM, Richard Lahrson wrote:
I never liked the feel of RC paper.
Most of the darkroom workers on the list
don't do analog darkroom prints commercially.
Considering the hassle we go through setting
up the darkroom, I see no reason, at least for me,
to use RC paper.
I got a question about Kodak T-8 polysulfide toner:
How long does it take to provide archival protection?
It takes 20 minutes to change color without heating.
Plus how toxic it T-8? Do I need gloves? Gloves are
a hassle.
On Sun, Aug 8, 2021 at 12:20 AM `Richard Knoppow <dickburk@xxxxxxxxxxxxx <mailto:dickburk@xxxxxxxxxxxxx>> wrote:
Try fishing, good way to use up worms.
I will try to answer the question about RC print
flatness. It
depends on the weather. Because of the way RC paper is made it
seems to be more sensitive to humidity. I found that in
very dry
weather RC tends to curl up tightly and then relax when
there was
more moisture in the air. I don't know a good cure for this.
My technique with fiber paper is to flatten it in a dry
mounting press. This was originally a part of the procedure
I use
to dry mount pictures. One step is to dry out the mounting
materials and the print using a heated dry mount press. I
make a
sandwich of the print with a layer of release tissue over the
emulsion side and clean construction paper as an absorbent
layer
on the support side. This sandwich is placed in the heated
press
and the press closed by not locked and left for perhaps two
minutes. Then I take the sandwich out and place it under a
flat
weight, preferably one made of metal, and let it cool. I find
this will flatten the print and for some reason it stays flat
despite variations in humidity. The trick does not work on
RC I
think because there is no way to change the amount of
moisture in
the support.
BTW, the traditional way of drying fiber also plays a
part in
keeping it flat. That is drying on screens with the
emulsion side
facing the screen. This tends to equalize the rate of drying
between support and emulsion. If a fiber print is just hung in
air the emulsion side will dry much faster than the support. I
think something similar happens with old fashioned blotter
books.
The emulsion faces the glassine sheet and the support is
against
the blotter. Blotter books work pretty well but I don't use
them
because there is too much chance of contamination. At least
with
screens, especially plastic ones, one can wash them.
I agree that RC is much faster to work with than fiber,
mostly because the wash time is so short even when a wash
aid is
used for the fiber paper. BTW, wash aid is not necessary
for RC
and probably should not be used.
I don't know what the current thought on print life is
but
RC probably is nearly as long lived as properly processed
fiber.
If I had to make prints for archival purposes I think I would
still use fiber.
It seems to me the degradation of the images on RC due to
decomposition of the brightener in the support is very much a
thing of the past. However, for either kind of support
treating
the prints with a polysulfide toner is still good practice.
I don't know about the shelf life of wash aid. It probably
depends on how well the bottles are sealed. In general, I
don't
like old chemistry. At least with developer you can tell if it
works but its not so simple with other stuff except that
probably
sodium fixer will last for ever.
I would consider inks a can of worms. I am sure there are
research papers on ink life. I see degraded paper more
often than
faded ink but my experience is quite casual. I will be
interested
in what others think.
On 8/7/2021 10:02 PM, mark@xxxxxxxxxxxxxxxxxx
<mailto:mark@xxxxxxxxxxxxxxxxxx> wrote:
> Ok, it is time to open the preverbal can of worms question.
> Just how long will an RC print last. Trying to find
reliable
> data seems to be a problem. One one side you get its trash,
> and on the other it will last 70 years or so. One side says
> fiber base will last 500 years, but some of the really early
> prints are less that 200 years old.
>
> I also know that outgassing was a real problem with the
early
> RC prints. No doubt about that, but I also know the
technology
> has improved. If RC has improved to a 70 year life, and our
> current variety of (gasp) digital prints are in the 70 year
> range (and I read something about inks outgassing as
well), why
> do art galleries seem to accept a digital print, but an RC
> print with roughly the same life is scorned.
>
> RC prints have so many advantages from an ease of use,
that its
> tough not to consider them. It's also possible my data
is flat
> out wrong. It is also possible that art galleries
perception
> is also not in touch with reality. Though a painting can
last
> for hundreds of years without issue, photography isn't so
> fortunate.
>
> In Fort Worth the Kimball Museum of Art has paintings
from the
> 1400s that look like they could have just dried. I doubt
any
> form of photography can touch that. Like many I sang,
please
> don't take my kodachrome away, but they didn't listen. For
> fiber to actually last longer, it has to be properly fixed,
> washed and toned. RC is far more tolerant of mistakes,
and yes
> we all make them. Be interested on all your thoughts.
>
> Question 2 I have some Ilford Rapid fix that I have had
for a
> long time. One has been opened but not been mixed into
> solution. It is still in the original container, but
just not
> used. The other is still sealed. Is either any good?
>
> BTW I have some Heico wash aid that I still have from a long
> time ago. Again the container has been opened, but the
> chemicals have not been mixed with anything. Not sure how
> sensitive either fix or a wash aid might be to such
conditions.
>
> Finally a sink update. Its almost complete. I have one
door
> on the unit to build and install, but other than that
> construction is complete. It worked out that I have three
> levels and the sink. The levels are rock solid and can be
> extended out to make it easier for one to proceed to the
next.
> There is about 8 inches between levels. Should allow
rooms for
> my hands to work in the gap if needed. A 16x20 tray fits
> perfectly. Give a developer, stop and fix tray, with the
sink
> being a wash or holding station of just water. For fiber
> prints or toning, I had to accept a reset. That way I
can use
> a wash aid, toning and final wash. Anything bigger than
16x20
> will need to be single tray processed. That is ok. I can
> build a tray for the larger sizes if needed. Truthfully I
> think its probably unlikely.
>
> Today I got the water ready, and tomorrow the drain
system will
> be dealt with. I had to use a normal faucet, instead of a
> system I came up with that as soon as hot water got to the
> sink, it would be the same temp as it was when I last
shut it
> off. A conventional faucet was more practical, but I did
get a
> side sprayer to help with clean up. I think the wife
will like
> this much better. We all know happy wife, happy life.
>
> None of it was particularly hard for me, but it was the
type of
> work that can be frustrating. A 16th too long in one
place and
> it hits on a support. Push to hard, and the nails bend.
None
> of that was a surprise. I knew up front I was working with
> warped wood and scrap many would have discarded. Yet I
find a
> sense of satisfaction of making what would have been
trash into
> something useful, even if it isn't fine furniture.
>
> Yes its taken time, but I have added a great deal of
storage,
> made the darkroom more efficient and made the wife happy
in the
> process. That makes the time and effort worth it. Looking
> forward to using the 4x5 field camera soon
>
>
>
> Thanks for your comments in advance
>
> Mark
>
> KG5VE 73
>
>
>
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-- Richard Knoppow
dickburk@xxxxxxxxxxxxx <mailto:dickburk@xxxxxxxxxxxxx>
WB6KBL
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