> I was trying some platinotype paper with a pure palladium and noted
> streaking on the final print. A few of the strokes of the brush were
> evident in the highlight areas of skies. Am I not applying enough
> sensitizer ? I am using a 7x17 negative and am using 36 drops of ferric
> oxalate #1 solution, no restrainer, and 36 drops of palladium and 3 drops
> of hydrogen peroxide. I applied the sensitizer with a puddle pusher
> initially and then smoothed it out with a hake brush and then air dried
> with a hair dryer. This normally does not happen with Bienfang so perhaps
> the platinotype paper requires more sensitizer. Any one know? I have heard
> the hydrogen peroxide must be fresh in order to act as a restrainer. Is
> this true and does the age of the H2O2 matter at all?
> Stephen Harrison
>
Stephen,
Beinfang has a much different thickness than other paper and so the
sensitizer will penetrate the papers differently. It may have only to do
with the time that you allow the solution to soak in before drying. Do
you dry the front and the back? A good back side drying will sometimes
get rid of streaking.
It may also be that you need to mix your solution more before appling it
to the paper. If the H2O2 is not mixed in evenly than you will have areas
that got restrained and others that didn't. The freshness of the peroxide
is quite important. If it is old and opened, you should consider buying a
fresh bottle. It only cost .33 to .50 cents a bottle.
And then again, it may all be cause by the extra brushing. I
have also seen that Beinfang can also handle more brush work than other
papers, not because it is stronger but perhaps because the sensitizer can
only soak so far into the paper. Different papers require different soak
and dry techniques to give you a good coating.
EJ Neilsen
ejnasn@laplaza.org
http://www.busdir.com/ericneilsen/index.html