Re: (Gum) Multi prints???

I'd agree with Mark's supposition that a gum duotone does require using both
a positive and negative, if what you're looking for is a very strong duotone
effect. For example "Clouds, New Jersey":

http://www.alternativephotography.com/artists/dave_rose/dr_clouds.html

This image was originally shot on 2 1/4" x 2 1/4" Kodachrome, a photo of
white clouds and blue sky. The Kodachrome was enlarged directly onto lith
film, creating a 15" x 15" negative. That negative was contact printed onto
lith film, creating a positive 'mirror' image.
Exposure 1: Cyanotype 7 min.
Exposure 2: Gum, red pigment 7 min.
Exposure 3: Gum, yellow pigment 2 min.
The first two exposures were made using the negative, the third using the
positive.

The final print is radically different from the original scene, with wildly
false colors. To the casual observer, it's believable, since similar
effects can be seen during sunrise or sunset. It's a good illustration of
the creative possibilities that gum and cyanotype offers, using B&W
negatives and a few pigments.

A more subtle duotone effect can be had using a single negative with
multiple printing techniques. I especially like using earth pigments
(umber, sienna, etc..) to build a strong image with good detail and color in
the highlights. Then print blue or blue/black using a much weaker exposure,
limiting the effect to shadows and midtones. This creates a subtle color
shift from shadows to highlights and gives the image strong contrast.

Example:

http://www.alternativephotography.com/artists/dave_rose/dr_north_fork.html

Pigments used were Burnt Sienna, Raw Umber, and Carbon Black with Winsor
Blue, with three exposures in gum.

Best regards from Big Wonderful Wyoming,
Dave Rose

Loris,

I am going to put my neck on the chopping block and venture to say that yes,
you would get a higher DMax with a more heavily pigmented mix (up to point
of
failure/washing off), but that would not necessarily mean a lower contrast
negative would be required, since the exposure scale would have more to do
with
the dilution of the dichromate than the amount of pigment—exposure scale and
DMax are different beasts.

With regards to duotone prints, I think that you would find that converting
an image to duotone might be a good way to get a sense of what the two color
combinations would look like, but I don't think that a duotone image as a
negative would be possible to work with—I think it would take a negative and
a
positive—just as full color gum takes 3 separation negatives.

Best Wishes,
Mark Nelson
Precision Digital Negatives
PDNPrint Forum @ Yahoo Groups
www.MarkINelsonPhoto.com

In a message dated 12/13/05 7:41:56 AM, loris_medici@mynet.com writes:

> My understanding is: "Because you can't get acceptable dmax without
> using a very high contrast (heavily pigmented) emulsion, and when you
> print with such an emulsion you have to use a very low contrast negative
> - which will cause loss of local contrast and delicate tonal gradations
> + increase the risk of flaking, giving you a grainy print".
>
> BTW, here's my question: I plan to print duo-pigment gums, a bluish dark
> gray (Schmincke Neutral Gray #785, PR251 + PB60 + PG7) for shadowns and
> a reddish brown (Schmincke Madder Brown #670, PR206) for highlights. I
> will print using digital negatives. Is there any way I can use
> Photoshop's Duotone image mode in order to design/predict the results
> and design curves/negatives giving that particular look in my monitor?
>
Received on Wed Dec 14 12:35:59 2005