U of S | Mailing List Archive | alt-photo-process-l | RE: Potentially stupid pt/pd question

RE: Potentially stupid pt/pd question

> Camden,  This is NOT the witness protection program, so it is OK to say
> the
> name of the dealer.

True.  However, I've always had great experiences with this company, and
the last thing I want to do is badmouth them on the alt photo list.  I'd
like to think it was an isolated incident, which it may or may not be, and
move on.  If I have any future troubles with this merchant, I'll let
everyone know.  Until then, I'll keep their name anonymous.

As far as the paper itself goes, the coventry vellum is actually quite
nice in terms of look and feel.  As long as I can get a decent print with
it, I'll be happy.  :)

> Dmax is influenced by more than one factor; blend of PT and PD, humidity
> of
> paper during exposure. Palladium IS FASTER at high humidity and Platinum
> is
> faster at LOWER humidity. (That's why it is best to include a coating
> mixture when asking for help)

I didn't know the ratio of pt to pd made a difference in dmax, although
it's not all that surprising to me.  I've been using Dick Arentz's pt/pd
contrast mixtures, and in this case the 2s mixture.  This translates to a
ratio of 6 pd:6 ferric oxalate:1 Na2 (5%).

> Properly used heat will stop the coating solution from soaking into the
> paper.

What exactly do you mean by properly used heat?

> If a paper clears more slowly than others that you use, just make sure and
> give it the required time or solution concentration, that is the only
> concern. It is possible to make too strong of a clearing bath just like it
> is possible to leave it too long in the tray. : (

Could you elaborate on this?  What are the consequences of each?  Which do
you think I should stick with?  Is there an easy way to tell which is the
better choice for this paper, aside from appearance (from an archival

Camden Hardy