Re: Glass for UV exposure frames?

From: Eric Neilsen (e.neilsen@worldnet.att.net)
Date: Sat Dec 04 1999 - 02:06:59 /etc/localtime


Jonathan Hall wrote:

> I use 1/4 inch plate glass and get an average of 2 to 6 minute exposures
> with palladium paper made with good old standard Bostick & Sullivan
> chemistry. The paper is Cranes Platinotype.
>
> I use 40 watt BL bulbs from Sylavania.
>
> Curious if anyone else uses these bulbs and what there printing times are as
> it seems people are having longer exposures than I. Could it be the climate
> I live in that allows such short exposure times. I can not see how that is
> possible but have found all kinds of invisible variables throught the last
> eleven years.
>
> Sincerely,
> Jonathan

Jonathan, I think that you'll find that several people use those particular
bulbs. I used them myself and still have them around. I am currently printing
with the Super Actinic lamps. The 2 to 6 minutes exposures that you mention are
on the faster side but in no way out of line with normal printing. You did not
mention your lamp to glass/contact frame distance.

And Yes, it could be climate, but you did not mention it either. Some people
may be drying their paper and printing with lots of platinum, this will give a
longer printing time. You may be using only palladium
and air drying your paper to a "dry" state but one that still has a high RH.
There are indeed may aspects that will change your print speed such as
temperature and dilution of your developer as well as choice of developer.

This says nothing about personal taste in the printing style. You may have also
seen Jeffrey posting information on optimizing solutions and concentrations of
ferric oxalate which should open the eye of the printers out there that many
many aspects of our process affect printing speed.

Happy printing

EJ Neilsen

--
Eric J. Neilsen
4101 Commerce Street, Suite #9
Dallas, TX 75226
214-827-8301
http://home.att.net/~e.neilsen



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