[alt-photo] Re: Dmax for silver paper

[Richard Knoppow]

----- Original Message ----- 
From: "Le Globe Trotteur" <unglobetrotteur at hotmail.com>
To: "The alternative photographic processes mailing list" 
<alt-photo-process-list at lists.altphotolist.org>
Sent: Saturday, January 14, 2012 7:01 AM
Subject: [alt-photo] Re: Dmax for silver paper


Ok, now I am very confused. Should I use my flat dryer or 
throw it away?
I also have another ferrotype dryer that is a drum but it's 
all manual. No
motor. My father in law found it in a dumpster. I have no 
idea on how to use
it. There's canvas all around the drurm. It also has a heat 
setting.

Let's see if I can summarize.
Put my fiber glossy print in photo flo. Do not squeegee it.
Lay it flat and wet onto a cold flat ferrotype dryer. 
Squeegee it.
Close the canvas (or maybe not). Turn on the heat and wait 
for the print to
pop.

I will also use a chrome polish to clean up my ferrotype.

Now Etienne suggested to lay it flat on a piece of glass. 
Would a piece of
glass from a frame work? or does it have to be special 
glass?

Thanks.
Pierre

     I know the dryer being talked about. It does tend to 
run hot but the old drum dryers did too. Heat is not 
necessary to ferrotype prints.
     The material the plate is made of is important; the 
easiest to use plates are bright chrome plated with a mirror 
smooth finish. The finish of the plate is molded into the 
gelatin of the print so the print will be no glossier than 
the surface of the plate.
     Chrome plates need no treatment other than scrupulous 
cleaning. Other types of plates, including glass, and the 
ones called Japanned plates, need waxing. There are many 
forumlas for the wax and several kinds were put up 
commercially. If you do not wax glass the print will stick 
to it so tightly that it can't be removed without damaging 
it. Real chrome plates may be difficult to find.
    Nearly all printing paper has a gelatin overcoating 
meant to protect the emulsion from abrasion. This layer also 
carries materials used to give paper a matt surface (as 
differentiated from texturing which is done to the Baryta 
layer). "Glossy" paper has not surfacing material in it. The 
hardness must be correct. If a cold plate is used it may be 
necessary to use a fixing bath without a hardener. The paper 
should be treated in a solution of wetting agent such as 
Photo-Flo for a couple of minutes and then placed on the 
plate sopping wet. It needs to make good contact all over. 
It is then squeegeed to the plate, removing as much excess 
water as possible. I've seen both flat and roller squeegees 
recommended and think it makes no difference. Be careful of 
new black rubber squeegees because they can leave marks on 
the back of the print. If done properly the print will pop 
off the plate when dry. If things are not right the print 
will come off with matt areas. These are caused either by 
air trapped under the print or where for any reason the 
print has not made good contact with the plate.
     High heat is not good but the plates can be heated 
gently to speed up drying.
     The large drum type dryers used for photo-finishing had 
adjustable heat and speed. All used a belt of canvas or 
similar material to hold the paper to the drum. Matt surface 
prints were dried with the emulsion facing the belt, glossy 
prints with the emulsion facing the drum. Old literature 
will tell you that photo-finishers had trouble with dryers 
because prints would stick or become discolored (plumming) 
or the gloss was not good. Several brands of treatment for 
prints were sold.
     Plumming comes from overheating the emulsion in drying. 
It comes from a change in the structure of the silver. Some 
papers intended for mass photo-finishing contained 
anti-plumming agents and there were modifications of the 
fixing bath to avoid it. I can try to find the references. 
Plumming was also a problem with early dry mounting tissue 
because the temperature was too high. Plumming is never a 
problem when room-temperature drying is done.
     For whatever reason glossy RC paper has a glossier 
finish than I have ever seen on a ferrotyped fiber print but 
you can come close.

--
Richard Knoppow
Los Angeles, CA, USA
dickburk at ix.netcom.com