Re: pigments for gum and PDN

Hi Kees,
All curves are from one coat only, as I am first interested in how each
color behaves individually. When I finish that, I will then see (by
printing side by side old way/new way) whether my findings hold true for
multiple coats.

I know in a sense they do, because in the past I always had to develop my
magenta coat for a longer period of time. That was my final coat on a
tricolor gum. For some reason I thought that the magenta coat would "stain"
more, but never suspected it would be faster than the other coats because I
had always read the order of fastest to slowest colors put red towards the
slow end.

If it were pigment lightness/darkness that affected speed, I would think
yellow would expose more quickly, which it doesn't. I have not tested an
opaque red vs an opaque yellow (e.g. cadmium) to see if opacity has some
effect. But I can only test one variable at once. However, I have curved
two yellows, an arylide and a semi opaque, and those curves are quite
similar, which leads me perhaps erroneously to believe still that the color
is a filter of its own nature, like filters you put on front of a camera
filter and change the tonal range on BW film.

I've finished the cyano coats (Fab Artistico Traditional White Cold Press
ONLY because I have run out of AEW hot pressed sized paper) and found one
thing for sure--this paper requires a 15 minute exposure instead of a
comparable 6 minute exposure on Platine, and Platine is a more gorgeous
thalo. Side by side, the PDN curve wins over my old curve. First layer
only, though and two more to go.
Chris
----- Original Message -----
From: "Kees Brandenburg" <ctb@zeelandnet.nl>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Saturday, June 11, 2005 6:12 AM
Subject: Re: pigments for gum and PDN

> Hello Chris
> Did you make your curves from a one coat gumprint? As the tonal range
> gets longer with more coats curves might be more accurate when measured
> and calculated after more than one coat (i.e. with your usual/preferred
> number of coats). Never tried it though.
>
> At what point do the curves for the individual colors differ?
>
> -kees
>
>> Today I print a side by side gum my old way (one curve for all three
>> layers, black ink only neg on Photo Warehouse film)and then with all
>> three layers done with their own color and curves (PDN method, colorized
>> negs with 3 separate curves and 3 separate printing times, no black ink,
>> Pictorico film), to see if there is a benefit with gum this way or not.
>> I have no clue. I am going to predict that gum is such a variable
>> process that it does not matter, being able to take care of these
>> variables through development and by eye, but I'd love to be proven
>> wrong. I know with cyano, silver, palladium and solarplate the PDN
>> system works like a charm. I also know that at the least I have learned
>> lots more about how gum and color respond by doing it.
>
>
>
Received on Sat Jun 11 07:08:28 2005