RE: question for silver gelatin users

-----Original Message-----
From: Ryuji Suzuki [mailto:rs@silvergrain.org]
Sent: Monday, 29 November 2004 11:22 p.m.
To: alt-photo-process-l@sask.usask.ca
Subject: Re: question for silver gelatin users

From: Kate M <kateb@paradise.net.nz>
Subject: RE: question for silver gelatin users
Date: Mon, 29 Nov 2004 22:38:23 +1300

Thanks for your response... It's always interesting to compare what
people do (against what I tried, currently do, and thought about).

> Sizing related:

> - how do you size? (brush, roller, dipping, etc.)
> I size by bath. Two coats, 12-24 hours drying between.

Is it better than brush application? Or is it just to save work? I
tried sizing by immersion but unless I size small pieces and hung dry,
there is no way to dry the paper without damaging it. (The sizing
solution sticks paper to whatever after drying.) I ask this because I
sometimes suspect that quality/uniformity of sizing affects uniformity
of emulsion coating rather significantly.

It's more even than brush application. I size rather small pieces
really, up to 1/2 full size paper sheet. As I use 300gsm watercolour
paper I don't have trouble with damaging it. I usually immerse it face
up, then flip to face down, draw it out over the edge of the bath to
remove excess on the surface, then allow to drip from one corner before
hanging. Any drips that from on the bottom edge I wipe off before they
set. The second time, I hang from the opposite edge.

> Emulsion coating related:
> - how much solution do you coat (specify size)?
> Per suare metre? I don't measure....

Per square (deci)meter or 22x30 inches or 80 square inches or whatever
unit... but if you don't measure...

For my current chlorobromide enlarging emulsion, standard coating weight
is 80-100ml per sq. meter (2.5+g AgX/sqm). 100ml gives me very nicely
dense black in shadows. But this level of coating can be achieved with
two thick coats or 3+ thin coats using foam roller. I wonder if this is
what people do as well. (I used to make emulsion thicker than typical
and also used to make thicker single coats but I didn't like the
results. My current emulsion is not very optimized but the image looks
crisper, the emulsion is considerably easier to make also taking less
time to make a batch.)

I find two thinner coats much easier to get even than one thick one.
Less streaks and better density in the print.

> - how do you coat? (brush, roller, dipping, etc)
>
> Brush first, then roll for a smooth surface. I find that applying by
> roller I always get bubbles. Can't get a decent smooth surface roller
> here (or can't find where to get one)

Doesn't the emulsion stick to the roller? (What kind of roller is it?)

Not much. This way, most of the emulsion goes onto the paper rather than
into the roller!!! It's a small open cell foam roller - the cheap
disposable kind. It leaves a slightly textrured surface. You have to
coat and roll very quickly to avoid the emulsion setting before you
roll. I think the temperature controlled environment helps.

 Quite a bit of emulsion gets wasted...

That's one reason why I didn't pursue the roller method.

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