Re: Indigo

I've been offlist for a few days and just caught the tail end of this,
so maybe someone already said this, but Winsor & Newton Indigo isn't
actually Indigo (PB66, which you wouldn't want anyway because it's a
fugitive color, as is the genuine indigo which the PB66 replaced
sometime in the 19th century) but is a convenience mixture, like most of
the "Indigo" paints that are offered. It contains lamp black,
quinacridone violent (PV19), and ultramarine violet (PV15).

Like Dave and Keith, I prefer to mix my own "indigo"-like colors by
mixing blue (usually indanthrone, PB 60, or ultramarine) and black, but
I use ivory black, which is more transparent than lamp black; I don't
like the lamp black because it renders anything it's mixed with opaque,
and I prefer transparency.
Katharine

Dave Soemarko wrote:
>
> You could also add a little quinacridone red as real indigo has a touch of
> red. How much of it is up to your liking. The color of real indigo ranges
> from purple to violet. In an acidic environment, the flowers are redder, and
> in a more alkaline environment, the flowers are bluer. I believe this is the
> same principle used in lithmus paper also.
>
> Of course most "indigo" colors don't use real indigo plant anymore as the
> manufacturing is complicated yet the color is non-permanent.
>
> Dave S
>
> ----- Original Message -----
> From: "Keith Gerling" <keith@gumphoto.com>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Thursday, January 22, 2004 10:58 PM
> Subject: RE: Indigo
>
> > Indigo is the only pigment I've encountered that flakes whenever I've used
> > it on any kind of paper. I'm probably on record as saying that ANY
> pigment
> > can be used with gum, but the truth is I've never had any success with any
> > indigo. Honestly, before I tried indigo, I always wondered what "flaking"
> > was when I heard it discussed regarding gum printing. Someone
> (Katherine?)
> > mentioned here that modern indigo contains lamp black. Maybe that
> > contributes to the problem (although I actually haven't had that many
> > problems with lamp black on the few occasions I've used it.)
> >
> > This is what I do to achieve an indigo type color: mix 1 part pthalo blue
> to
> > 4-5 parts ivory black. It's very close to indigo.
> >
> > -----Original Message-----
> > From: ericawd [mailto:ericawd@mem.quik.com]
> > Sent: Thursday, January 22, 2004 9:13 PM
> > To: alt-photo-process-l@sask.usask.ca
> > Subject: Indigo
> >
> >
> > I am having trouble with achieving the right gum/pigment mix with
> indigo.
> > I work with gram(s) pigment to ml(s) gum ratios. (e.g.. Windsor Blue 1
> > gram to 12 ml). I have tried more than one mix and none have come out
> > satisfactory.
> >
> > Does anyone use WN Indigo and if so what ratio worked?
> >
> > Candace Spearman
> >
> >
> >
> >
> >
Received on Thu Jan 22 23:08:01 2004