RE: Potentially stupid pt/pd question
Eric, Thanks for the information. I'll be doing some more tests tomorrow morning to see if I can get better results under a few different conditions. I suspect the problem is that I'm allowing the emulsion to absorb into the paper too much, so I'll play around with heat and humidity. I'll let you know how it works out. Camden Hardy camden[at]hardyphotography[dot]net http://www.hardyphotography.net On Sun, October 15, 2006 11:04 pm, Eric Neilsen wrote: > > > >> -----Original Message----- >> From: Camden Hardy [mailto:camden@hardyphotography.net] >> Sent: Sunday, October 15, 2006 2:44 AM >> To: alt-photo-process-l@usask.ca >> Subject: 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. :) >> > > You may have gotten good service before and you'll probably get good > service > in the future, but in the process of withholding the name, you may be > setting someone else up for poor service in regards to papers. > > >> >> > 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%). >> > > So other than the Na2, there is NO PT in your prints. The ratio (or use of > or not) can help to say why you are seeing a particular effect; like > reverse > of the blacks with only PD. The blend of PT and PD, along with humidity, > will produce a print that has certain speed and contrast characteristics. > > >> >> > Properly used heat will stop the coating solution from soaking into >> the >> > paper. >> >> What exactly do you mean by properly used heat? >> > > Properly used the heat will stop the penetration of the coating solution > into the paper with no fog or grain. Improper use can cause fog by cooking > the paper with an airstream that is too hot. > > >> >> > 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 >> standpoint)? >> > You can find out what is in the paper and judging by your experience with > your distributor, I'd call Legion directly or look it up on the web site > but > I don't know if they have it up on the site. > > You can soften the paper and make it extremely hard to handle without > damaging either the whole piece or opening up the door for surface > abrasions. If you are using an acid bath to clear, you may damage the > paper > leaving it hard and brittle. > > > > > Eric Neilsen Photography > 4101 Commerce Street > Suite 9 > Dallas, TX 75226 > http://e.neilsen.home.att.net > http://ericneilsenphotography.com > Skype ejprinter > > >
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