Re: (Gum) Tonal scale

From: Yves Gauvreau ^lt;[email protected]>
Date: 11/28/05-11:56:25 AM Z
Message-id: <020301c5f445$0d5c22f0$0100a8c0@BERTHA>

Joe,

I got about the same 6 steps you mention and I understand the gum process as
a large number of factors influencing the end result.

I kind of expected that the multiple exposure wouldn't be linearly additive.
I'm beginning to think that the gum process is only for those willing to
spend a large amount of time experimenting with the process trying to learn
how to actually "create" types of image they like. Because there seems to be
so many many things you can do with the process that I can't believe one
would stick with only one. I must say I admire people who did or are doing
this, it take a lot of dedication and probably some kind of passion.
Obviously, I have doubts about my own capacity and determination especially
that I know so little.

Yves

----- Original Message -----
From: "Joe Smigiel" <jsmigiel@kvcc.edu>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Monday, November 28, 2005 12:09 PM
Subject: Re: (Gum) Tonal scale

> Yves,
>
> You may expect to get *about* 6 steps of a Stouffer 21-step scale
> printed on average with a good exposure for gum. (This works out to be
> about a 3-stop range.) This will vary with pigment and paper, etc., as
> well as pigment concentration and duration of exposure as David
> suggests. You will probably also find that even using the same pigment
> mix, the density gain of later coats never quite matches the first coat
> density increase due to the effect of the first layer making the surface
> slicker and acting as a size for later coats. As the paper gets
> slicker, the gum does not adhere as well, OTBE.
>
> "Your mileage may vary."
>
> Joe
>
>
> >>> davidhatton@superonline.com 11/28/05 10:31 AM >>>
> Hi Yves,
>
> It's my understanding that at least three exposures are necessary for a
> full tonal print. Could be more or less but it goes something like
>
> Highlights :- little pigment + long exposure - say 2 minutes
> Mid tones :- More pigment + less exposure - say 1 minute
> Shadows :- Max pigment + least exposure - say 30 secs.
>
> Understand this is the principal not necessarily the practice.
>
> Hope this helps
>
> David H
>
> Yves Gauvreau wrote:
> > Hi everyone,
> >
> > I wonder if someone knows what kind of tonal scale (range) one
> > can expect with gum printing when using a certain number of exposure
> for
> > the same print???
> >
> > I assume density will build up, thus increasing the range between the
> > white of the paper and the darkest areas. I suspect also that these
> > multiple exposure are not linearly additive meaning that if I get a
> > density of say 1.0 somewhere on the first exposure I wont get 2.0 with
>
> > the next exposure.
> >
> > Thanks
> > Yves
> >
> >
> >
> >
> >
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Received on Mon Nov 28 12:15:54 2005

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