"Dan Quinn" wrote in message
om...
(Fred) wrote

Dan wrote:
Is that the only reason you are using KRST? You're
not interested
in the archival properties it can confer?

Acutally that's the reason I started using selenium.

Any addition of selenium will extend a silver images
already long
lifespan. I doubt any disagreement of that.

A just perceptable, subtel
darkening in the shadows will not confer archival
properties. That
amount will not protect the most vunerable highlight
areas.

Are you saying that the archive effect of the toner is
proportional to
the toning effect?

At least that is the conventional wisdom. To read
quickly an
explanation of the preferential toning behavior of
selenium, one
might think thin areas of silver are immune. Perhaps
the dense areas
exert some sort of gravitational pull and hoard the
selenium untill
they've had their fill.

I like the idea that the selenium toner serves to
protect the print
from oxidizing gases. The implication is that the
protection covers
the whole spectrum of silver density on the print even
though the
selenium increases the shadow densities in prints with
little
or no change in the image tone.

I believe that implication correct, but for some reason
though, tests
have showen that the highlight areas are still vunerable.
Keep in
mind we have to start a very long lasting base silver
image.


Silver-gelatine with no after treatment can last
generations,
even a century or more in good condition. I think
there are quite a
few who do tone but not for it's lengthening the life
span
of the print.
BTW, have you considered dilution and carry out of
the solution
when costing that KRST?
Dan

I just divided the suggested number of prints capacity
by the cost.
I've never used selenium toner untill last week. I
guess if I want
more toning effect from selenum, I'll try a warmer tone
paper.

Nelson's Gold Toner may be your ticket. It is a sulfide
plus Gold
toner. I've read that it can be used at room temperature
although more
usually at 100-110 F. Ready-Mix can be bought from
Photographer's
Formulary. Cost per print is a small fraction of KRST. For
more
Info search this NG for, nelson's gold .
I compound all my own chemistry. I've all the chemicals
for Nelson's
but have yet to mix the toner. I'm wraped up in refining
my print
developer test methods and testing some new formulas.
Dan

Nelson's is a good toner where partial toning is desired
because it does not split tone. It also gives a somewhat
different color than other direct toners. The best source of
instructions is the patent. Some of the reprinted
instructions in Kodak handbooks leaves out the very
important step of refixing the prints after toning. This is
vital if they are to be permenant.
The patent number is USP 1,849,245 This is available from
the U.S. Patent and Trade-Mark Office site at
http://www.uspto.gov you will need a browser plug-in to
display the fax tiff files. The best is Alternatiff,
available as freeware off the web. Do a Google search to
find it. The tiff files can be viewed off line and printed
using the Windows imaging program.
A good toner for protective purposes is Kodak Brown Toner
or Agfa Viradon. These are both concentrated polysulfide
toners. Both tone uniformly. The color of the image will
depend on the color of the original but the shift is greater
on cold tone papers than from KRST. A visible change is
sufficient to impart substantial protection to oxidation.
Both toners must be used with a 10% sulfite bath following
toning as a sort of stop bath. Polysulfide toners have the
peculiar property of toning faster as they become exhausted
or diluted, so, any toner retained in the paper when it
enters the wash bath will continue to tone untill
substantially washed out. If washing is too slow it will
cause a peach-colored stain in the highlights. The sulfite
bath eliminates this problem. The current toner recommended
by IPI for microfilm use is a polylsulfide toner. KBT,
Viradon, or Kodak T-8 will all work. While KBT is used at
100F for rapid toning it will work at room temperature but
very slowly. This may actually be an advantage if one wants
just slight toning. No fixing is required after a
polysulfide toner. The main drawback to these two toners is
odor. The odor is not too strong unless the toner becomes
exhausted but there is still some "rotten egg" odor.


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Richard Knoppow
Los Angeles, CA, USA