Luis advocated using "generic colors," which promptly became "dry
pigments," which may or may not be what he meant. On the one hand, I have
never seen a line of "generic" paints ready mixed, like the generic catsup
at the supermarket, on the other hand, if Luis really meant dry pigment
(which may not be as much cheaper as he thinks),lots of dry pigment is
sold under brand names.
Today, for instance, I ordered some Daniel Smith dry pigment; a while back I
bought some packaged by Gamblin, and the store where I bought it had other
"brands" like Grumbacher. (If you want cheaper, order from Kremer, which
is indeed an excellent source for Kremer dry pigment.)
Next, you scientists are taking the word of someone who told someone
who claimed to have discovered that "none of the prepared pigments were
fine enough for gum"!? What?! More likely *the fella* wasn't fine enough for
gum -- he did something crude & his prints came out crude so he blamed Winsor
Newton.
Meanwhile, I'm pretty sure I said in February that Mark Golden of Golden
Paint company told me at College Art (wasn't anybody listening?) that any
dry pigment (as well of course as moist tube paint) we buy will be fine
ground at the factory way beyond the capacity of our medium to
differentiate. The problem, he said, the grainy look (and yes I do trust
this "expert"), would be from our not being able to *disperse* the pigment
thoroughly in the medium (gum arabic in the case of gum printing), as
there is a very strong tendency of finely ground pigment to clump. Some
kind of mutual attraction (electric? magnetic?). The dispersal, he said,
is much better done by machine at the factory -- which may in fact be what
your home ball millers are doing when they think they're grinding pigment.
Since I wanted to use dry pigment for some purposes, Golden suggested I
add a dispersal agent to help break up the pigment clumps, which I did,
but I found, as I have found several times before using other forms of
plain pigment packed with added dispersal agent (Createx, Guerra) that it
disperses the pigment particles right into the pores of the paper, and,
like the roach motel, they don't get out again.
This dispersal is not a problem with carbon printing, BTW, since the pigment
resides in the gelatine and the gelatine washes away -- doesn't get
into pores of the paper.
Finally, let me note that if you value your time at minimum wage rates
(& I value mine a bit higher), spending time ball-milling pigment to save
money compared to tube paints is a losing proposition. However, a mortar
and pestle does disperse well enough for most purposes, certainly with the
rough paper frequently used for gum....
Judy