Digital BW, The Print

Paul,

Thanks for your reply.

> http://www.paulroark.com/BW-Info/Pigment-dispersion.jpg

That diagram looks just like the Cab-O-Jet 300 black pigment as described in

http://nanoparticles.org/pdf/Kowalski.pdf  !   ;)


I found the introductory bit of the following article interesting (about 
manufacture and properties of carbon blacks) - 
http://carbon-black.org/carbonblackuserguide.pdf, especially the bit about 
size and aggregates and conglomerates.

> (Epson calls the edge treatment of its MK a "solubility" treatment --  
> which
> makes no sense for a pigment.)

Well, the borderline between 'soluble' and 'insoluble' is a bit gray, isn't 
it? Adding hydrophilic groups of various sorts makes the carbon black 
particles 'self-dispersing' in aqueous solution, by enabling hydrogen 
bonding with the water. So for most people, making the particles 'more 
soluble' is probably OK if not technically accurate.

I still haven't understood why smaller particles of carbon black are 
apparently blacker than larger particles. Good for us that they are, but I'd 
like to understand why.

Bob Frost.



----- Original Message ----- 
From: "Paul Roark" <paul.roark@...>