Re: Help with gum printing: was: Transparency

Charlie Goodwin wrote:
>
> Sorry to butt into a discussion I don't have a stake in, but the facts as stated below need "adjusting".
>
> > Transparent pigments simply disappear into a darker background.
>
> >... transparent pigments are transparent and will
> > be invisible over a darker background no matter how concentrated they
> > are printed
>
> > No matter how concentrated you make a transparent pigment, it will
> > always be transparent, because that's the inherent nature of the
> > pigment.
>
> I paint and I photograph, and use "transparent" pigments all the time, and may be able to make the facts a bit more "transparent" here.
>
>
>
> In the real world, the so called transparent pigments fall substantially short of that ideal. Some are pretty good, and can be treated as kinda transparent, but most are waaaay short of the performance of the dyes found in photographic filters.
>
> The best transparent pigment colors show their limitations when applied thickly. They exhibit a phenomenon known as "mass tone". Example, one of my colors is known as Indian Yellow, really Diarylide yellow PY83. Very thinly applied over a bright white paper, it makes a strong yellow. A bit more heavily it becomes a stunningly intense golden yellow. It just screams. It's addictive, so you think, I'm going to just gop it on and go into chromatic orgy mode. So, you gop it on and get.
>
> That's mass tone, seen in most so called transparent colors, a reflection seen best when a thick layer is just trowelled on. Even the best transparent colors don't quite match the performance of the best dyes.
>
> For the most part, most of what a painter would call a transparent color is semitransparent, and those known as semitransparent are semiopaque. Most opaque pigments fall short too, lacking the "covering power" one might wish.
>
> So - if you pile any transparent pigment, in oil or water medium, whtever , onto a black substrate thickly enough, you will see a mass tone, and in some colors, that mass toner will be surprisingly different from the color you expect.
>

Yes, of course, but you can't achieve masstone in gum printing, which is
the universe I thought this discussion was taking place within, and in
gum printing, transparent pigments remain transparent throughout their
range of printing concentration, meaning that they disappear against a
dark background. They blend with the colors underneath, but they aren't
visible above them, whereas more opaque pigments are visible over a
black background at even a low concentration. There are a number of
such pigments, which make up my own personal palette since I have always
preferred the look of printing with transparent pigments, which is
different from the look of printing with more opaque pigments.

However, I'm starting to fall in love with opacity for the first time as
a result of the experiments I've done for this thread, thanks Carmen!
There's something really interesting about the images that emerge this
way. It never would have occurred to me before, that this would be the
very best way to make very high-key images (mostly whites and
near-whites), much better than printing them dark on white, partly
because when you print a high-key image white on dark, you've got all
this paint and no paper, so there's something deeper and fuller and
richer about the image then when you've got a little bit of paint and
mostly white paper. It's just altogether a more interesting image. I'm
hooked on light on dark.

What I was trying to say to Dave was that I agree with him that both
transparent and opaque pigments can print a full tonal range, but what I
think is interesting is that they do it with a different effect. Of
course only pigments with some opacity can be used over a dark
background if you want the overlay to be visible. These "stated facts"
need no adjustment since they are based on my observations in years of
printing gum.

The statement that white paper adds to tonality is only half true; it
helps with the tones from midtones through highlights, when you're
printing dark on white, but the shadows must be made with paint covering
the white. When you're printing white on black, the black paper adds to
tonality in exactly the same way that white paper adds to tonality when
you're printing dark on white, but in the case of white on black, the
paper adds to the tonality from the shadows through the midtones, but it
doesn't help with the highlights; you have to make the highlights purely
from paint, overcoming the black. So to me the principle of paper and
tonality is exactly the same in either case, just reversed.

Katharine Thayer
Received on Wed Jan 19 11:44:55 2005