Judy very kindly sent me some very interesting information which I think is
highly significant
And tho my search for the Gamblin booklet was frustrating, it put in my
hands another fine item, an article titled "Factors Influencing the
Wash-Fastness of Watercolours" by Vincent Daniels, from "The Paper
Conservator 19, 1995, sent to me by a kind friend.
Here's an example:
"Most pigments have a broad range of pigment sizes and synthetic organic
pigments and carbon black particles are sometimes as small as 0.01u in
diameter. The ease with which particles stick to fibres increases as the
size of particle decreases. Jones reports that particles below about
0.2u are 'virtually impossible to remove from cotton cellulose except by
drastic mechanical action, and washing is difficult even with particles
as large as 5u.'"
[This is what I was trying to say about fine grinding with a ball mill.]
I got to thinking about particle size, is this another invisible joker in
the pack, could it explain why some colours stain more than others ,is
there an Ideal particle size for our processes,what is the largest size
before the colour becomes to gritty to use. How does one measure particle
size, is watercolour paint in fact ground to fine what is the size of the
particles in various paints such as acrylic, raw artists
quality pigments,etc, these are some of the questions that spring to mind.
I have on numerous occasions stated that the materials we use may not be ideal
for the purposes which we wish to put them,this is nobodies fault it is
just that the paint and papers have been made to satisfy a primary
application in
most cases once, thy have not been designed to be put down then removed
the paints are made to stain, and the papers are made to hold onto that stain,
it says much for the skill of photo alt workers that they have surmounted these
difficulties to a large extent ,but if we could obtain pigments that come
out of the paper cleanly and paper that does not hold onto the pigment
particles at all.then life could become a great deal easier for all
concerned.We have only then to solve the paper dimensional stability
problem to have a perfect printmaking process.
Has enybody out there got any information to share on these topics
pete