I forgot to address my response to the group as well, and so everyone
can follow along, here is that post.
-- Eric J. Neilsen 505-758-8868 http://laplaza.org/~ejnasn Date: Sun, 05 Apr 1998 09:21:56 -0600 From: Eric Neilsen <ejnasn@laplaza.org> Subject: Re: Pt/Pd Brush Marks: Humidity To: TERRY KING <KINGNAPOLEONPHOTO@compuserve.com> Reply-to: ejnasn@laplaza.org Message-id: <3527A194.2064F45E@laplaza.org> Organization: Eric Neilsen Photograper MIME-version: 1.0 X-Mailer: Mozilla 4.02 [en]C-DIAL (Win95; U) Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit References: <199804050630_MC2-38FC-C3ED@compuserve.com>Yes, every coating situation and its problems has its own answers. When I was printing on the west coast in the early 80's, we would dry the paper in a dry mount press heated to about 150 and then let it cool down before printing. This seemed to help some. Our RH was in the 80's much of the time.
one answer to brush marks is how the paper is dried. A quick drying of the front or sensitized side after a two minute soak, and then a complete drying from the back side, using a hair drier worked great. This helped to eliminate brush marks on several papers that I used.
TERRY KING wrote: > > During threads on brush marks it becomes clear that people's methods of > overcoming this difficulty relate very much to where they live. > > If one lives in Santa Fe with an ambient humidity of 5 going on 20 when > everybody feels hot and sweaty, it is clear that when you coat your paper > with solution the liquid is going to evaporate so quickly that it will not > sink very far into the paper. If you were to try that in London or Bath > where the average humidity is 60 and people start complaining when it > reaches 80, leaving the solution to dry naturally will take so long that it > will sink into the paper in an irregular manner leading to brush marks and > mottling. This effect is obviously also going to vary from one paper to > another as well. This is why I use a fan heater to dry my size and > solutions; in effect emulating Santa Fe conditions for platinum printing. > > Moral : humidfiers, fan heaters and hygrometers should be sold by suppliers > to the platinum printing industry. Now I am off to the garden centre to get > some photographic chemicals. > > Terry King
-- Eric J. Neilsen 505-758-8868 http://laplaza.org/~ejnasn