Digital BW, The Print

Steve,

You wrote:

>... another curious development to report regarding the
>VM 4.3 inks. My 7500 has been sitting unused for about 3 weeks now,
>until yesterday. When I turned it on it ran a cleaning cycle, I did
>a nozzle test...it was flawless. Nice suprise.

I find that also.  I've gotten so lazy and confident that I often don't even
bother with the nozzle checks.

> However, the test print I did on EEM came out greenish.

The only time I've seen color in the new VM 4.3/Ultra Tone inks is when the
damper allows some residual old ink to mix in.  This usually disappears
after the first few days of printing, however.  I'm not sure if some
hardened old pigment in the dampers could slowly "dissolve" (or get
re-suspended?) such that after a long time sitting it could affect the
color.

>It looked like the light M toner was weak, but there was
>no nozzle skipping, even with a loupe.
>I decided to procceed on the assumption that somehow some of the
>pigment has settled, either in the lines or the damper, so I took
>the dampers off and pulled about 30ml of ink through them. The ink
>in the LM damper was initially very transparent, like dye ink. As I
>pulled fresh ink into it, it darkened up and became more opaque.

>Subsequent test prints are better-but not quite as neutral as they
>were new, so I'm going to pull a bit more ink through the system to
>see if that helps.

>Any theories or guesses as to what caused this?

Not really.

The light toner is really dilute.  However, it still uses the same
RC-compatible, high-load compatible base.  As such, I would think that it
would be very unlikely to settle.  I do wonder what is different about this
new base, however.  I'll run the issue by MIS and see if Zeiss has any
ideas.

My 7500 with the VM 4.3/Ultra Tone inks has been idle for nearly 10 days
now, so the next time I use it I'll print a purge pattern to see if I can
detect any color changes.

Paul
http://www.PaulRoark.com