Re: White pigmet for one-layer bichromate.

Pawel Gega wrote:
>
> Hello,
>
> What is the best white pigment for white gum layer on black paper. Is the
> titanium white the cleanest?

Hi Pawel,
I would recommend titanium white (PW6) over zinc white (whose pigment
number I don't remember off the top of my head) which are really your
only two choices. (Zinc white is often called "Chinese white") The zinc
is less opaque than the titanium and, in my experience with two
different brands, tended to dichromate stain as well. You want a good
quality brand because the inferior brands/student lines often add chalk
to their titanium white, as the pure titanium oxide is quite expensive.
>
> o, is it possible to get white and black tones similar classical B&W ?

It depends on the paper you use, the pigment mix, the dichromate
concentration, etc, how long a range you can get in one coat. The only
white on black I've done so far have been on Arches cover, which is a
very coarse open paper and as such didn't give a very large range of
tones. I have an example of how the paper printed for me both unsized
and sized here:

http://www.pacifier.com/~kthayer/html/Whiteblack.html

I got mixed up and used a negative instead of a positive for these
prints, even though I had the positive sitting right there, and that's
why the shadows are white instead of black. The original picture was of
three brown eggs and two white eggs sitting on a white table.

I was always going to go back and experiment more with printing white on
black, and ordered some smoother papers for the purpose, but haven't
found the time so far.
Katharine Thayer
Received on Sun Nov 13 12:20:43 2005