RE: Tri-Curious Seeks Other Tri-Quad Curious Gummists

[Don Bryant <dsbryant@bellsouth.net>]

Henry, 

>
I often print landscapes, with simple CMY or CMYK negatives colour-separated
in Photoshop. Normally the colour balance is pleasing, except for the sky.
Grey skies are fine, but when the image includes a blue sky, the cyano layer
by itself looks just right - and the magenta layer then prints quite a lot
of magenta over it. Presumably this is because the prussian blue of
cyanotype is not at all close to the true cyan which is assumed by the
separations.

Of course the problem is easily solved by gently brushing away the excess
magenta during development - but does anyone else have the same problem? Or
a better solution?
>

I've had similar problems having to brush off the magenta in sky areas. I'm
not sure that the Prussian blue is the total cause but it maybe. I'll have
to test with Thalo. One thing that I've done is to decrease the amount of
magenta pigment while increasing the amount of gum and also raising the
developer temperature to about 80F for the first half of the development
time.

Don Bryant